Any of the archdevils or demon lords should do the trick. I would say asmodeus is the strongest among them if that matters. There is also Tiamat the devil Dragon and god of the chromatic dragons.
If you go by the numbers, Tiamat is tops. As for which is most powerful, that depends entirely on encounter design and how the DM runs the monster. Tiamat would lose in Orcus' lair and vice versa.
Tiamat is the strongest (not necessarily most powerful) printed fiend. Asmodeus has not had his stats printed, but is probably just as strong and holds more power.
Isn't there a hierarchy of Devils, though? In some of the older editions, Tiamat was granted rulership of the 1st plane of Hell. There were 9 planes of Hell total with Asmodeus in the lowest one. By implication, a bunch of archdevils therefore had more hellish authority than Tiamat based on which plane they ruled. How much of this has changed?
Tiamat has residency/imprisonment on the first level of hell through some contract with Asmodeus but is only ruler of the area that's within her domain, Zariel is in charge of the layer as a whole. The details of the relative power of the rulers of the layers is unclear, but at the very least Asmodeus is at the top.
I remember reading somewhere that WotC wasn't going to make stat blocks for all of them for some reason relating to not being interested in players focused on killing Gods or near-Gods (or what have you). Because that's what happens - you give something a stat block and people are going to try to defeat it.
So, I guess, at least for now, you're going to have to homebrew a stat block for them if you want them in your game. You'll also have to determine who is where in the pecking order. MToF has some stuff on the Blood War, but I don't remember it laying out who was where and all that. I haven't read it in quite a while, though, so there's that. I also don't know if any other 5e sources go into their hierarchies either. I certainly don't know anything about other editions, so someone else can speak to those.
Obox-Ob, he may’ve been nearly killed a while back, but he was the first true Demon Prince, the only shame is that his CR is 22, where he deserves at least CR 27
I'd use a Succubus. They are only Challenge Rating 4, but they are very *sneaky*. They don't scare anyone. They do not take sides in the Blood War. They don't have holdings to defend, they have no need to plot and scheme to maintain their power.
Their only real interest is the souls of mortals. They tempt, corrupt, and then consume the souls of mortals who surrender to them. They use their powers rarely, hide their true forms, and flee long before they can be attacked. Fiends don't age. A Succubus can be ancient and plan for things over the long term. Their most dangerous power is social. They only need to influence people a little and they can have huge numbers of innocent people doing their bidding without ever revealing their true nature.
Succubae can spy on their targets for as long as they like. They can lurk in the Ethereal. They can join a party of adventurers and provide assistance for years and years, learning everything about their target in the process. Once they have enough to go on they can start corrupting their victim, taking even more years and slowly bringing them to the point where they *want* to surrender their souls.
A Succubus can start a Cult. They can direct it from within, posing as one of the least important members and using nothing more than words and promises to keep control. The Cult may think they are serving a deity who is all hearts and flowers, cute little puppies, and rainbows, and never know what they really serve.
These Fiends are rarely the King's most trusted advisor, but that advisor will need someone, if not for advice, then for someone to relax with and get some relief from the pressure. A succubus can be a great counsellor. They know what evils lurk in the hearts of others. They have plenty of experience with evil.
A succubus going after a player character is a menace. They can follow along, sending assassins, rescuing the character, and helping to hide the body. Succubae know where the bodies are buried, they may have been the ones who put them there in the first place. They can have access to huge amounts of wealth and magical items and lead the character right to them. Succubae don't need a whole lot, and the power of their target is largely irrelevant.
There are ways to detect succubae. Some are pretty easy to come by. Mortals able to detect the true nature of a succubus are all the more delicious when they fall. Once a succubus has finished gathering information they will know just what lies to tell. After all, what good and just Paladin could resist as sweet and helpless little boy or girl who can look them in the eye and tell them just what they want to hear?
"Yes, I am a Fiend, I am Evil, beyond redemption, and I just want to consume your soul, but I am cursed and I wish I could change things. If only someone like you, someone strong, and wise, would give me a chance... I would be ever so grateful, I could help you in so many ways. I know I could be whatever you want me to be, do whatever you want me to do, and in the end Love would overcome all obstacles. Won't you please help me?"
Tiamat is a *god*. She has immense power. Yet for all her power she has less influence over mortals then a simple CR 4 succubus with time on their hands could have.
I need to know, because I'm making a homebrew magic item that's Artifact rarity and requires attunement to a bloodhunter. PLEASE HELP ME.
In dndbeyond, the highest-CR monster with the "fiend" tag is https://www.dndbeyond.com/monsters/zariel . Really any of the nine ( https://www.dndbeyond.com/sources/mtof/the-blood-war#LordsoftheNine ) would be super strong.
Is that the level of power you're looking for?
Either Asmodeus (Devil) or Demogorgon (Demon). I would say Asmodeus since he's the only Fiend that's also a God.
Any of the archdevils or demon lords should do the trick. I would say asmodeus is the strongest among them if that matters. There is also Tiamat the devil Dragon and god of the chromatic dragons.
Erinyes could be what you might be looking for. Unless you are wanted the most powerful fiend in all existance then the above answers would suffice.
-Sol
It might help if you specified what you mean by "powerful." Power can be defined several different ways. Do you just mean highest CR?
Once you're over CR20, pretty much anything goes.
"Not all those who wander are lost"
I mean like CR30.
From the published content that I have access to, it looks like Tiamat is the only CR 30 Fiend.
Zariel, Orcus, and Demogorgon are the next highest, all at CR 26.
Again, that's just in the published content that I, personally, have access to. I don't know about others.
You could probably also create one if you really wanted.
That's odd, aren't demon princes in older versions of D&D much stronger than Tiamat? What accounts for the lower CRs of Demogorgon and Orcus?
If you go by the numbers, Tiamat is tops. As for which is most powerful, that depends entirely on encounter design and how the DM runs the monster. Tiamat would lose in Orcus' lair and vice versa.
"Not all those who wander are lost"
As far as I know, Tiamat is currently an actual god. Asmodeus might be on par with Tiamat, but the others are another rung below.
Tiamat is the strongest (not necessarily most powerful) printed fiend. Asmodeus has not had his stats printed, but is probably just as strong and holds more power.
Isn't there a hierarchy of Devils, though? In some of the older editions, Tiamat was granted rulership of the 1st plane of Hell. There were 9 planes of Hell total with Asmodeus in the lowest one. By implication, a bunch of archdevils therefore had more hellish authority than Tiamat based on which plane they ruled. How much of this has changed?
Tiamat has residency/imprisonment on the first level of hell through some contract with Asmodeus but is only ruler of the area that's within her domain, Zariel is in charge of the layer as a whole. The details of the relative power of the rulers of the layers is unclear, but at the very least Asmodeus is at the top.
I remember reading somewhere that WotC wasn't going to make stat blocks for all of them for some reason relating to not being interested in players focused on killing Gods or near-Gods (or what have you). Because that's what happens - you give something a stat block and people are going to try to defeat it.
So, I guess, at least for now, you're going to have to homebrew a stat block for them if you want them in your game. You'll also have to determine who is where in the pecking order. MToF has some stuff on the Blood War, but I don't remember it laying out who was where and all that. I haven't read it in quite a while, though, so there's that. I also don't know if any other 5e sources go into their hierarchies either. I certainly don't know anything about other editions, so someone else can speak to those.
Sorry for not being much help! ;)
Eh, its OK.
Obox-Ob, he may’ve been nearly killed a while back, but he was the first true Demon Prince, the only shame is that his CR is 22, where he deserves at least CR 27
WiSP
I'd use a Succubus. They are only Challenge Rating 4, but they are very *sneaky*. They don't scare anyone. They do not take sides in the Blood War. They don't have holdings to defend, they have no need to plot and scheme to maintain their power.
Their only real interest is the souls of mortals. They tempt, corrupt, and then consume the souls of mortals who surrender to them. They use their powers rarely, hide their true forms, and flee long before they can be attacked. Fiends don't age. A Succubus can be ancient and plan for things over the long term. Their most dangerous power is social. They only need to influence people a little and they can have huge numbers of innocent people doing their bidding without ever revealing their true nature.
Succubae can spy on their targets for as long as they like. They can lurk in the Ethereal. They can join a party of adventurers and provide assistance for years and years, learning everything about their target in the process. Once they have enough to go on they can start corrupting their victim, taking even more years and slowly bringing them to the point where they *want* to surrender their souls.
A Succubus can start a Cult. They can direct it from within, posing as one of the least important members and using nothing more than words and promises to keep control. The Cult may think they are serving a deity who is all hearts and flowers, cute little puppies, and rainbows, and never know what they really serve.
These Fiends are rarely the King's most trusted advisor, but that advisor will need someone, if not for advice, then for someone to relax with and get some relief from the pressure. A succubus can be a great counsellor. They know what evils lurk in the hearts of others. They have plenty of experience with evil.
A succubus going after a player character is a menace. They can follow along, sending assassins, rescuing the character, and helping to hide the body. Succubae know where the bodies are buried, they may have been the ones who put them there in the first place. They can have access to huge amounts of wealth and magical items and lead the character right to them. Succubae don't need a whole lot, and the power of their target is largely irrelevant.
There are ways to detect succubae. Some are pretty easy to come by. Mortals able to detect the true nature of a succubus are all the more delicious when they fall. Once a succubus has finished gathering information they will know just what lies to tell. After all, what good and just Paladin could resist as sweet and helpless little boy or girl who can look them in the eye and tell them just what they want to hear?
"Yes, I am a Fiend, I am Evil, beyond redemption, and I just want to consume your soul, but I am cursed and I wish I could change things. If only someone like you, someone strong, and wise, would give me a chance... I would be ever so grateful, I could help you in so many ways. I know I could be whatever you want me to be, do whatever you want me to do, and in the end Love would overcome all obstacles. Won't you please help me?"
Tiamat is a *god*. She has immense power. Yet for all her power she has less influence over mortals then a simple CR 4 succubus with time on their hands could have.
<Insert clever signature here>
Tiamat isn't in Hell because she defaulted on a contract. She killed one of the giant gods, who cursed her with his dying breath.