It's entirely possible the character is driving toward the sword (this is the DM Zone on the forum so we can rock spoilers) because rather than dithering about the B-lister power factions of Avernus, they want to SAVE A CITY OF (relatively, in my game residents of Elturel are sort of pompous holier than thous types blind to their own flaws) INNOCENTS SOULS FROM BEING CAST INTO THE RIVER STYX TO BE CONSCRIPTED INTO HELL'S LEGIONS AND LIKELY OBLIVION AS CASUALTIES IN THE BLOODWAR. Given that urgency I could see many characters wanting to get onto the mission and not be distracted by Hell. I mean the DMs diversions could be interpreted as temptations off the path with the cost being more souls falling into the river as the war rages below it.
Now I appreciate some folks are presuming the player is cheating or meta-ing prior knowledge of the game to "speed run" so that poses the question: when called on it, how does the player justify the character's actions, Moreover, FWIW, the paths in Avernus are basically the lock and key set up so it's not so much an intervention into DiA as written but a return to the format of the module. If the character is trying to bypass those steps on the path ... that'll get the party dead as the paths scale along the mentioned 5-13 progression in that chapter.
As far as "player agency", player agency is not a license to bully or browbeat other players in character and meta into following one players whims. That's simply deflected by the DM preferring all players coming to a consensus in your game. Of course, it sounds like the players play style has been cast as diametrically opposed to the DMs, which is the real matter to contend here, which I take up at the end.
Concurring with the current that just because the party isn't chewing the scenery you "put so much work in" (DMs really need to let their worlds and "genius" stay wet clay and stop putting their imagination into kilns ... it just makes for fragile prep. DMs should be as curious about what's going to happen when the players meet their game as the players themselves, but that's my own manifesto).
All that aside, the real issue requiring resolution: your loaded assessment of the player makes clear you don't like the player. Your criticism of the player in this game and (more extensively) in other games and outside the game may be valid, though it's laid on hella thick. So whatever the pathology of the dynamic, the one incontestable fact here is you just don't like the player (this isn't a criticism of you as a person, again your sketch may well be valid, but what matters is you finding no path to reconciliation with this personality/behavior). For any but the Most Zen DM (tm) it's really hard to entertain the presence of someone whom the DM regards so dimly. It pains you to play with the person and there actually isn't some DM ASMR (tm) that will whisper a problem player into a good player. That sort of reconciliatory interpersonal work requires a lot of frank emotional openness between the injured and offending parties and some notes on a message board aren't going to give you that skillset (though it can come in time). It's best to just explain the player's play style pains you (and if you have the backing of your table speak on the table's behalf) you think it's probably best the two of you parted ways (this would logically recuse yourself from the grim dark game you don't want to be part of anyway). The way you cast this player, it doesn't sound like any constructive feedback would be heeded so it's best just to cut this and try to recover some fun for the rest of the game.
This still may not get the party to play tourist in the world you want to guide them through though. Again, realize the precepts of DiA. The characters are in Hell to save a city from a diabolical plot. Most sane characters who call the Prime Material Plane home would likely want this incursion done as quickly and as efficiently as possible and not linger to smell the roses. I mean think of the way Avernus is presented in the module, the exhaustion mechanics tied to despair etc. Why would anyone in their right mind want to stay. DiA is basically a commando raid with a clear objective, it's not a Long Range Recon Patrol where they venture long and wide learning about the Plains of Avernus (maybe in the sequel if you gave them good reason to linger in the aftermath). "Get 'er done" is a completely reasonable tempo given the stakes presented in the module as written.
If a player (or a DM for that matter) is taking control of the adventure, railroading the players onto a path that was not intended to be traveled on, and is forcing everyone to play along, then they shouldn’t be playing.
Talk to this player. Explain that D&D is a team game, and that them railroading everyone is not the pathway to an enjoyable campaign. If they refuse to listen, then you have a choice. Either deal with it, or kick them from the table. The DM has the responsibility and obligation to set the borders, and to kick those who cross them. You can kill their character, have the players kill them, turn them into a villainous NPC, or whatever. As long as you talk to this player first, you can and should take whatever actions necessary to relieve the other players of his behavior.
Thanks for the advice guys. To answer a couple more questions:
The player hasn't read DiA AFAIK, except that I know he has looked up the stats for the aforementioned magic item (AKA the Sword of Zariel). For anyone who knows the module you'll know that relocating it isn't really an option without heavily modifying and homebrewing the module since the entire 4th chapter revolves around retrieving it. How you get there is easily changed though, which is why the characters attitude of "you made a mistake so I wanna kill you" doesn't hold up because the are several ways of reaching the players goal, one mistake isn't a mission failure.
Overall at the table, people are having fun with the adventure itself but they are frustrated that several of them wanted to pursue alternate paths and sidequests but have been shut down. That is except the one who has been receiving threats to his character, who is decidedly uncomfortable with problem players attitude and rightly so.
Another worrying thing (this is more spoilery & plot relevant but isn't relevant to the problem player being problematic per say so treat this as an aside) is that problem players goal he's beelining towards isn't even the default ending of "redeem Zariel, save the city" which is made so much easier by retrieving the sword, it's that he wants to kill Zariel. Which is fine as a goal but like, to achieve that you have to spend more time doing sidequests & roleplay to gain allies which he's actively avoiding. So he's just leading the players towards their inevitable deaths? This is also not the goal that about half the players want (But again, loudest voices etc.).
End of the day I'm gonna ask the opinions of some of the quieter players to get a full rounded view on it, then speak to him about it. I'm personally being made uncomfortable because I've had to deal with one of my players thinking the other is going to murder their character, obviously that player is very uncomfortable, and on the whole I feel the other players agency & creativity is being stifled by this guys attitude, which is detrimental to the campaign as a whole.
I learned the hard way that you can't force your players to enjoy the playstyle you lay out for them. You have to adapt to what they enjoy about your world and do that. In this case though, it sounds like you have the backing of some players and you need to solve a problem in your group of players. I would first talk with the group about the rules of hostility between party members. If someone objects to have that element in the game, you make it clear that you will not tolerate that at all. If the railroader has an objection to that, he needs to go. There are optional topics, that players can object to having in their game, like sexual content or violence and hostility between the group. If the whole group agrees to keep that element in the game, you enable your players to deal with the railroader on their own terms and he will realize that he is one character vs several. If there are objections to hostility in the group and everyone agrees to play nice, you have given the other players the sign that they do not need to be bullied and they can then in game renegotiate the path the group is taking. If they still don't speak up against the rushing of content, the last thing you can do without going nuclear is to give them the characters the insight, how difficult their current path is and how much easier and rewarding different paths might be. If they still follow the loudest voice, it's their choice and you can't do much but adapt your world and think about how to keep the integrity of your world in tact but allow the players to survive the choice they made. Maybe they are being captured and have to fight for amusement or they are forced to hide in the underground and come back later.
Killing Zariel herself is a bit difficult, one of the goals of the Adventure is to redeem her. The only way to kill a creature of the outer planes is to go to the specific plane they came from, and Zariel didn't start out in Avernus. She came from Heaven, and I'm not sure which of the 7 she started out in. The Adventure has no side quest for that.
Tell him that "Balder's Gate, Ascent into Heaven" hasn't been published yet, and it's unlikely that even when it gets published, there will be a quest for killing Zariel, but maybe she could be redeemed there too, so once the Adventure comes out, (it would be written for 3-5 level 17 characters) you'll be delighted to run it.
They seem to have read enough to have become fixated on getting the sword and doing what they want as quickly as possible. They are acting very selfishly in a cooperative game, so it's got to be sorted out.
Allow the players to split up if they want to. If the problem dude wants to steam ahead and the others want to explore, then split the game. Tell the problem player that you'll run a session with them to cover their time apart from the group, and then focus on the other players. If they say they don't want to wait, tell them to join the other players on their quest then.
Warn them that PVP is not acceptable at the table, neither as a threat or an action, unless it's a duel (agreed on by both parties). If they take a swing at the innocent party member, then rocks fall, make a new character, try not to make them a d*ck this time. Obviously, only do this if you've warned them against these actions!
Killing Zariel herself is a bit difficult, one of the goals of the Adventure is to redeem her. The only way to kill a creature of the outer planes is to go to the specific plane they came from, and Zariel didn't start out in Avernus. She came from Heaven, and I'm not sure which of the 7 she started out in. The Adventure has no side quest for that.
Killing Zariel is indeed difficult, purely due to her sheer power & speed let alone the armies she commands. But now she is an Archdevil there is nothing to say she cannot be killed while in Avernus. This is her home plane now for all intents & purposes. The book does mention this as a potential outcome, albeit a very ill advised one. It's entirely doable at the end of the adventure, but it will depend upon the characters playing smart and planning out how they intend to pull off such a feat. Right now this is lacking :/
Edit: Also I wanna stress this, even if Zariel was just a Solar, there is no lore I am aware of in 5th edition to suggest she would survive being killed. Unlike Demons & Devils outside their native plane, nowhere does it state any celestials are reborn in their homeland. Except there is one huge notable exception: If you kill Lulu in this adventure specifically, she Deus Ex Machina gets resurrected and appears at the citadel.
The last time Solars were said to reform in the heavens was 2e.
Zariel is given stats. She's a CR 26 Lawful Evil Devil, and she has Truesight, Telepathy, and one of her Legedary actions allows her to Teleport. The player characters will be at 13th level then they meet her. The Encounter Builder Tool says that 5 level 13 characters of any class against her and 5 CR 20 Pit Fiends would get them 860,000 xp each.
It is also worth mention, that as the General of Avernus, she's going to have more help than that, she's got every Devil in Avernus to call upon. Just fighting her alone is a Deadly encounter. I said "a bit difficult" near as I can figure, it's nearly impossible.
Why aren’t the rest of the characters putting him in his place in game? Or if that doesn’t work either telling him to beat it or putting him in the dirt in game?
The best way to deal with a problem player is to gang up and dog pile on him in game.
Zariel is given stats. She's a CR 26 Lawful Evil Devil, and she has Truesight, Telepathy, and one of her Legedary actions allows her to Teleport. The player characters will be at 13th level then they meet her. The Encounter Builder Tool says that 5 level 13 characters of any class against her and 5 CR 20 Pit Fiends would get them 860,000 xp each.
It is also worth mention, that as the General of Avernus, she's going to have more help than that, she's got every Devil in Avernus to call upon. Just fighting her alone is a Deadly encounter. I said "a bit difficult" near as I can figure, it's nearly impossible.
I mean, this is exactly why the book mentions at least one way of building a literal army to go and face her if that's what you plan on doing. Even Bel's default stance in the book is "Go and redeem her because a confrontation is too dangerous for me" and he's the supposed ruler of the Dark Eight (Although their relationship is somewhat complicated). I will say though, as written Zariel is a somewhat reckless show off who will go out and 1v1 Balors in the middle of a battlefield & everyone around her knows to stay the hell away, so there's nothing to suggest it's her style to fly around with Pit Fiend body guards when they could be doing far more useful things commanding her armies. Therefore in the scenarios presented by the book, assuming she will have such help is entirely DM homebrew (perhaps justified given her supposed power & influence - but still homebrew). That doesn't mean there won't be legions of powerful devils surrounding her at all times though, it's just there is only one Pit Fiend General mentioned to be in the fight (the albino one).
Anyways I've been aware of this since the beginning & ensured multiple factions each have ways of evening the scores, not just Tiamat's forces as the book suggests. It just relies on the players actually seeking them out before the confrontation, which by the looks of things will be after they retrieve the sword and not before (This actually lengthens the campaign since as written, Tiamat's forces take 9 days to muster. If they were intending to speed run their time in Avernus, they should get her on side first, not last, though they don't know this beforehand). I'm gonna have Olanthius tell them to gather at least some allies before challenging Zariel as a last ditch attempt to say "Go do the other content!", and hope they actually take the plot threads I've been handing them for once.
Update on talking to my players: I've spoken to all of them except the problem one and all of them are concerned about the threats he's doled out to one of the payers, most of them can list things they would have gone & done if he wasn't shutting them down, and half of them say his attitude is making the game less fun and enjoyable in general, so definitely going to talk to him about it soon.
First off, Zariel may not have 5 Pit Fiends as a personal guard, but you did say she has one, the Albino Pit Fiend. Next up, if assuming that she has any other help is a House Rule, just like my contention that that she would be able to call on her own armies. You can't have it both ways. Do remember, other than some of the player characters, everything in Hell is Evil, so why would they get help of any kind? Devils are not known for being helpful, unless you mean helping people who ask them for help die. So thus, the only way for the players to kill Zariel, is to face off against her and the Albino Pit-fiend by themselves at level 13.
The entire point of that sub-plot is to redeem Zariel, not to kill her. It appears that there is only one player who wants to kill her, so why exactly are you planning to talk about it with him?
If it was up to me, the moment he said he was going to have his player character attack another player character I would have discussed it with him then, with the group, and if we couldn't agree about playing the story out as intended in private, he would be shown the door. I have better things to do with my time, like make things fun for the people who are enjoying the game.
First off, Zariel may not have 5 Pit Fiends as a personal guard, but you did say she has one, the Albino Pit Fiend. Next up, if assuming that she has any other help is a House Rule, just like my contention that that she would be able to call on her own armies. You can't have it both ways. Do remember, other than some of the player characters, everything in Hell is Evil, so why would they get help of any kind? Devils are not known for being helpful, unless you mean helping people who ask them for help die. So thus, the only way for the players to kill Zariel, is to face off against her and the Albino Pit-fiend by themselves at level 13.
The entire point of that sub-plot is to redeem Zariel, not to kill her. It appears that there is only one player who wants to kill her, so why exactly are you planning to talk about it with him?
I can tell you haven't read or played the Descent into Avernus module and do not understand the factions at play. Furthermore, assuming all evil creatures are on the same side is a vast oversimplification and misunderstanding of the core conflicts of the Nine Hells. That is, every powerful Devil wants to depose the Archdukes above them, every Archduke wants the throne of Asmodeus, and on top of this the whole realm is in a never ending conflict with the abyss (The Blood War), and filled with extraplanar mercenaries who fight in that war (the Yugoloths). If you have very little knowledge of the setting or scenario, please cease to comment on what is and isn't homebrew, since you clearly have no idea what you're talking about.
If it was up to me, the moment he said he was going to have his player character attack another player character I would have discussed it with him then, with the group, and if we couldn't agree about playing the story out as intended in private, he would be shown the door. I have better things to do with my time, like make things fun for the people who are enjoying the game.
He's not attacked the player yet he's just sent a very long and specific threat to them. Despite this I'm already doing what you described so yes, that's what I'm doing.
The thing is the Sword of Zariel has to deem who wields it "worthy." It's problematic, because Zariel herself is a sort fanatically driven type, and behavior like this offending player's character (to read them generously) is exactly what leads to her downfall. If this player wasn't abusive to the table, this would have been a fun angle to play (basically the character mirrors Zariel's flaws and suffers a lesser infernal fate).
Other thing you have in your DM toolkit: when the sword is presented to the PCs it's made clear whoever wields it will be transformed by the will of the sword. Be very strong with that admonition, the faithful and Lulu can all attest this would be a no saving throw, the DM has already determined the template (basically Aasimar) the character will become, if your offending player is still makes the grab, and you for some reason find them "worthy" BOOM they're a pacifist whose soul is overwritten with the celestial spark of the sword and the character's desire is now to seek restoration of the weapon to Zariel. It's sort of a curse to the character's motives. This admonition is clear in the adventure as written so it's not like you're contriving a particular fix for the offending character, it's just that the player never really understood the adventure and in the end taking hold of the sword is actually a sacrifice of the self. This may be over the player's head, but the party might actually find this ironically amusing.
Of course, beforehand, make it clear to your player that intra character threats and violence will mandate a break in action so all players can discuss their comfort level with the actions proposed or threatened, giving the opportunity for your players to police their own dynamics. And if any intra player threats are made, those should be fielded to the DM and the DM will have likely a more intensive discussion with the table about the tables position on coercive conduct and any sanctions that may occur. Maybe the player will just feel unable to play under the social contract as it's been required to evolve and either self-remove or if they persist in an abusive manner it should be clear that the player has received plenty of notice before DM removed.
It's entirely possible the character is driving toward the sword (this is the DM Zone on the forum so we can rock spoilers) because rather than dithering about the B-lister power factions of Avernus, they want to SAVE A CITY OF (relatively, in my game residents of Elturel are sort of pompous holier than thous types blind to their own flaws) INNOCENTS SOULS FROM BEING CAST INTO THE RIVER STYX TO BE CONSCRIPTED INTO HELL'S LEGIONS AND LIKELY OBLIVION AS CASUALTIES IN THE BLOODWAR. Given that urgency I could see many characters wanting to get onto the mission and not be distracted by Hell. I mean the DMs diversions could be interpreted as temptations off the path with the cost being more souls falling into the river as the war rages below it.
Now I appreciate some folks are presuming the player is cheating or meta-ing prior knowledge of the game to "speed run" so that poses the question: when called on it, how does the player justify the character's actions, Moreover, FWIW, the paths in Avernus are basically the lock and key set up so it's not so much an intervention into DiA as written but a return to the format of the module. If the character is trying to bypass those steps on the path ... that'll get the party dead as the paths scale along the mentioned 5-13 progression in that chapter.
As far as "player agency", player agency is not a license to bully or browbeat other players in character and meta into following one players whims. That's simply deflected by the DM preferring all players coming to a consensus in your game. Of course, it sounds like the players play style has been cast as diametrically opposed to the DMs, which is the real matter to contend here, which I take up at the end.
Concurring with the current that just because the party isn't chewing the scenery you "put so much work in" (DMs really need to let their worlds and "genius" stay wet clay and stop putting their imagination into kilns ... it just makes for fragile prep. DMs should be as curious about what's going to happen when the players meet their game as the players themselves, but that's my own manifesto).
All that aside, the real issue requiring resolution: your loaded assessment of the player makes clear you don't like the player. Your criticism of the player in this game and (more extensively) in other games and outside the game may be valid, though it's laid on hella thick. So whatever the pathology of the dynamic, the one incontestable fact here is you just don't like the player (this isn't a criticism of you as a person, again your sketch may well be valid, but what matters is you finding no path to reconciliation with this personality/behavior). For any but the Most Zen DM (tm) it's really hard to entertain the presence of someone whom the DM regards so dimly. It pains you to play with the person and there actually isn't some DM ASMR (tm) that will whisper a problem player into a good player. That sort of reconciliatory interpersonal work requires a lot of frank emotional openness between the injured and offending parties and some notes on a message board aren't going to give you that skillset (though it can come in time). It's best to just explain the player's play style pains you (and if you have the backing of your table speak on the table's behalf) you think it's probably best the two of you parted ways (this would logically recuse yourself from the grim dark game you don't want to be part of anyway). The way you cast this player, it doesn't sound like any constructive feedback would be heeded so it's best just to cut this and try to recover some fun for the rest of the game.
This still may not get the party to play tourist in the world you want to guide them through though. Again, realize the precepts of DiA. The characters are in Hell to save a city from a diabolical plot. Most sane characters who call the Prime Material Plane home would likely want this incursion done as quickly and as efficiently as possible and not linger to smell the roses. I mean think of the way Avernus is presented in the module, the exhaustion mechanics tied to despair etc. Why would anyone in their right mind want to stay. DiA is basically a commando raid with a clear objective, it's not a Long Range Recon Patrol where they venture long and wide learning about the Plains of Avernus (maybe in the sequel if you gave them good reason to linger in the aftermath). "Get 'er done" is a completely reasonable tempo given the stakes presented in the module as written.
Jander Sunstar is the thinking person's Drizzt, fight me.
If a player (or a DM for that matter) is taking control of the adventure, railroading the players onto a path that was not intended to be traveled on, and is forcing everyone to play along, then they shouldn’t be playing.
Talk to this player. Explain that D&D is a team game, and that them railroading everyone is not the pathway to an enjoyable campaign. If they refuse to listen, then you have a choice. Either deal with it, or kick them from the table. The DM has the responsibility and obligation to set the borders, and to kick those who cross them. You can kill their character, have the players kill them, turn them into a villainous NPC, or whatever. As long as you talk to this player first, you can and should take whatever actions necessary to relieve the other players of his behavior.
Thanks for the advice guys. To answer a couple more questions:
The player hasn't read DiA AFAIK, except that I know he has looked up the stats for the aforementioned magic item (AKA the Sword of Zariel). For anyone who knows the module you'll know that relocating it isn't really an option without heavily modifying and homebrewing the module since the entire 4th chapter revolves around retrieving it. How you get there is easily changed though, which is why the characters attitude of "you made a mistake so I wanna kill you" doesn't hold up because the are several ways of reaching the players goal, one mistake isn't a mission failure.
Overall at the table, people are having fun with the adventure itself but they are frustrated that several of them wanted to pursue alternate paths and sidequests but have been shut down. That is except the one who has been receiving threats to his character, who is decidedly uncomfortable with problem players attitude and rightly so.
Another worrying thing (this is more spoilery & plot relevant but isn't relevant to the problem player being problematic per say so treat this as an aside) is that problem players goal he's beelining towards isn't even the default ending of "redeem Zariel, save the city" which is made so much easier by retrieving the sword, it's that he wants to kill Zariel. Which is fine as a goal but like, to achieve that you have to spend more time doing sidequests & roleplay to gain allies which he's actively avoiding. So he's just leading the players towards their inevitable deaths? This is also not the goal that about half the players want (But again, loudest voices etc.).
End of the day I'm gonna ask the opinions of some of the quieter players to get a full rounded view on it, then speak to him about it. I'm personally being made uncomfortable because I've had to deal with one of my players thinking the other is going to murder their character, obviously that player is very uncomfortable, and on the whole I feel the other players agency & creativity is being stifled by this guys attitude, which is detrimental to the campaign as a whole.
I learned the hard way that you can't force your players to enjoy the playstyle you lay out for them. You have to adapt to what they enjoy about your world and do that. In this case though, it sounds like you have the backing of some players and you need to solve a problem in your group of players. I would first talk with the group about the rules of hostility between party members. If someone objects to have that element in the game, you make it clear that you will not tolerate that at all. If the railroader has an objection to that, he needs to go. There are optional topics, that players can object to having in their game, like sexual content or violence and hostility between the group. If the whole group agrees to keep that element in the game, you enable your players to deal with the railroader on their own terms and he will realize that he is one character vs several. If there are objections to hostility in the group and everyone agrees to play nice, you have given the other players the sign that they do not need to be bullied and they can then in game renegotiate the path the group is taking. If they still don't speak up against the rushing of content, the last thing you can do without going nuclear is to give them the characters the insight, how difficult their current path is and how much easier and rewarding different paths might be. If they still follow the loudest voice, it's their choice and you can't do much but adapt your world and think about how to keep the integrity of your world in tact but allow the players to survive the choice they made. Maybe they are being captured and have to fight for amusement or they are forced to hide in the underground and come back later.
Killing Zariel herself is a bit difficult, one of the goals of the Adventure is to redeem her. The only way to kill a creature of the outer planes is to go to the specific plane they came from, and Zariel didn't start out in Avernus. She came from Heaven, and I'm not sure which of the 7 she started out in. The Adventure has no side quest for that.
Tell him that "Balder's Gate, Ascent into Heaven" hasn't been published yet, and it's unlikely that even when it gets published, there will be a quest for killing Zariel, but maybe she could be redeemed there too, so once the Adventure comes out, (it would be written for 3-5 level 17 characters) you'll be delighted to run it.
<Insert clever signature here>
They seem to have read enough to have become fixated on getting the sword and doing what they want as quickly as possible. They are acting very selfishly in a cooperative game, so it's got to be sorted out.
Allow the players to split up if they want to. If the problem dude wants to steam ahead and the others want to explore, then split the game. Tell the problem player that you'll run a session with them to cover their time apart from the group, and then focus on the other players. If they say they don't want to wait, tell them to join the other players on their quest then.
Warn them that PVP is not acceptable at the table, neither as a threat or an action, unless it's a duel (agreed on by both parties). If they take a swing at the innocent party member, then rocks fall, make a new character, try not to make them a d*ck this time. Obviously, only do this if you've warned them against these actions!
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Killing Zariel is indeed difficult, purely due to her sheer power & speed let alone the armies she commands. But now she is an Archdevil there is nothing to say she cannot be killed while in Avernus. This is her home plane now for all intents & purposes. The book does mention this as a potential outcome, albeit a very ill advised one. It's entirely doable at the end of the adventure, but it will depend upon the characters playing smart and planning out how they intend to pull off such a feat. Right now this is lacking :/
Edit: Also I wanna stress this, even if Zariel was just a Solar, there is no lore I am aware of in 5th edition to suggest she would survive being killed. Unlike Demons & Devils outside their native plane, nowhere does it state any celestials are reborn in their homeland. Except there is one huge notable exception: If you kill Lulu in this adventure specifically, she Deus Ex Machina gets resurrected and appears at the citadel.
The last time Solars were said to reform in the heavens was 2e.
Zariel is given stats. She's a CR 26 Lawful Evil Devil, and she has Truesight, Telepathy, and one of her Legedary actions allows her to Teleport. The player characters will be at 13th level then they meet her. The Encounter Builder Tool says that 5 level 13 characters of any class against her and 5 CR 20 Pit Fiends would get them 860,000 xp each.
It is also worth mention, that as the General of Avernus, she's going to have more help than that, she's got every Devil in Avernus to call upon. Just fighting her alone is a Deadly encounter. I said "a bit difficult" near as I can figure, it's nearly impossible.
<Insert clever signature here>
Why aren’t the rest of the characters putting him in his place in game? Or if that doesn’t work either telling him to beat it or putting him in the dirt in game?
The best way to deal with a problem player is to gang up and dog pile on him in game.
I mean, this is exactly why the book mentions at least one way of building a literal army to go and face her if that's what you plan on doing. Even Bel's default stance in the book is "Go and redeem her because a confrontation is too dangerous for me" and he's the supposed ruler of the Dark Eight (Although their relationship is somewhat complicated). I will say though, as written Zariel is a somewhat reckless show off who will go out and 1v1 Balors in the middle of a battlefield & everyone around her knows to stay the hell away, so there's nothing to suggest it's her style to fly around with Pit Fiend body guards when they could be doing far more useful things commanding her armies. Therefore in the scenarios presented by the book, assuming she will have such help is entirely DM homebrew (perhaps justified given her supposed power & influence - but still homebrew). That doesn't mean there won't be legions of powerful devils surrounding her at all times though, it's just there is only one Pit Fiend General mentioned to be in the fight (the albino one).
Anyways I've been aware of this since the beginning & ensured multiple factions each have ways of evening the scores, not just Tiamat's forces as the book suggests. It just relies on the players actually seeking them out before the confrontation, which by the looks of things will be after they retrieve the sword and not before (This actually lengthens the campaign since as written, Tiamat's forces take 9 days to muster. If they were intending to speed run their time in Avernus, they should get her on side first, not last, though they don't know this beforehand). I'm gonna have Olanthius tell them to gather at least some allies before challenging Zariel as a last ditch attempt to say "Go do the other content!", and hope they actually take the plot threads I've been handing them for once.
Update on talking to my players: I've spoken to all of them except the problem one and all of them are concerned about the threats he's doled out to one of the payers, most of them can list things they would have gone & done if he wasn't shutting them down, and half of them say his attitude is making the game less fun and enjoyable in general, so definitely going to talk to him about it soon.
First off, Zariel may not have 5 Pit Fiends as a personal guard, but you did say she has one, the Albino Pit Fiend. Next up, if assuming that she has any other help is a House Rule, just like my contention that that she would be able to call on her own armies. You can't have it both ways. Do remember, other than some of the player characters, everything in Hell is Evil, so why would they get help of any kind? Devils are not known for being helpful, unless you mean helping people who ask them for help die. So thus, the only way for the players to kill Zariel, is to face off against her and the Albino Pit-fiend by themselves at level 13.
The entire point of that sub-plot is to redeem Zariel, not to kill her. It appears that there is only one player who wants to kill her, so why exactly are you planning to talk about it with him?
If it was up to me, the moment he said he was going to have his player character attack another player character I would have discussed it with him then, with the group, and if we couldn't agree about playing the story out as intended in private, he would be shown the door. I have better things to do with my time, like make things fun for the people who are enjoying the game.
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I can tell you haven't read or played the Descent into Avernus module and do not understand the factions at play. Furthermore, assuming all evil creatures are on the same side is a vast oversimplification and misunderstanding of the core conflicts of the Nine Hells. That is, every powerful Devil wants to depose the Archdukes above them, every Archduke wants the throne of Asmodeus, and on top of this the whole realm is in a never ending conflict with the abyss (The Blood War), and filled with extraplanar mercenaries who fight in that war (the Yugoloths). If you have very little knowledge of the setting or scenario, please cease to comment on what is and isn't homebrew, since you clearly have no idea what you're talking about.
He's not attacked the player yet he's just sent a very long and specific threat to them. Despite this I'm already doing what you described so yes, that's what I'm doing.
The thing is the Sword of Zariel has to deem who wields it "worthy." It's problematic, because Zariel herself is a sort fanatically driven type, and behavior like this offending player's character (to read them generously) is exactly what leads to her downfall. If this player wasn't abusive to the table, this would have been a fun angle to play (basically the character mirrors Zariel's flaws and suffers a lesser infernal fate).
Other thing you have in your DM toolkit: when the sword is presented to the PCs it's made clear whoever wields it will be transformed by the will of the sword. Be very strong with that admonition, the faithful and Lulu can all attest this would be a no saving throw, the DM has already determined the template (basically Aasimar) the character will become, if your offending player is still makes the grab, and you for some reason find them "worthy" BOOM they're a pacifist whose soul is overwritten with the celestial spark of the sword and the character's desire is now to seek restoration of the weapon to Zariel. It's sort of a curse to the character's motives. This admonition is clear in the adventure as written so it's not like you're contriving a particular fix for the offending character, it's just that the player never really understood the adventure and in the end taking hold of the sword is actually a sacrifice of the self. This may be over the player's head, but the party might actually find this ironically amusing.
Of course, beforehand, make it clear to your player that intra character threats and violence will mandate a break in action so all players can discuss their comfort level with the actions proposed or threatened, giving the opportunity for your players to police their own dynamics. And if any intra player threats are made, those should be fielded to the DM and the DM will have likely a more intensive discussion with the table about the tables position on coercive conduct and any sanctions that may occur. Maybe the player will just feel unable to play under the social contract as it's been required to evolve and either self-remove or if they persist in an abusive manner it should be clear that the player has received plenty of notice before DM removed.
Jander Sunstar is the thinking person's Drizzt, fight me.