(SPOILERS campaign 1 critical role) By the end of campaign 1 Vecna ascended to godhood (before he was some kind of saint and patron of evil wizards) . But that was Exandria’s Vecna, whose story diverges in many points from Oerth’s Vecna. So are there two Vecnas now? 

But Arkham the Cruel showed up in Descent Into Avernus, which means things that happen on Exandria can afffect the rest of the multiverse.

Quote from Lyxen >>

More seriously, what happens in specific campaigns stays in specific campaigns. I'm not following CR so I don't know hoe much of the campaign has been put in the sourcebook, but even if that storyline was in there, it would not mean anything as these are different worlds in any case.

 To catch you up on the specifics:

• Vox Machina (heroes of Critical Role campaign 1) defeat Vecna with the assistance of Arkhan the Cruel
• Arkhan the Cruel (Joe Mangoniello's character he plays in every campaign he's in) previously featured in Force Grey, a canon Faerun live play show. This is the same Arkhan that later appeared in Critical Role creating an FR >> CR link
• Arkhan stole the Hand of Vecna, replacing his own hand with it and planeshifted away
• He then appears in Descent into Avernus, sporting the Hand of Vecna which is explicitly stated he acquired on Exandria (the plane of Critical Role)

So there is a canon connection from Faerun to Exandria, back to a Forgotten Realms set adventure featuring the Hand of Vecna acquired from the Exandrian proto-deity rather than the Oearth archlich.

Quote from ESTRELARIUS >>

But Arkham the Cruel showed up in Descent Into Avernus, which means things that happen on Exandria can afffect the rest of the multiverse.

 This does create a bit of a weird wrinkle, because Oearth and Toril are explicitly in the same plane (but different crystal spheres). Theoretically there could be two Vecna's, or Vecna from Oearth went on to Exandria where he started causing trouble. It could be that Vecna is more of a title or mantle that some liches and wizards take up, like Xanathar.

Quote from Lyxen >>

Quote from Davedamon>>

Quote from Lyxen>>

More seriously, what happens in specific campaigns stays in specific campaigns. I'm not following CR so I don't know hoe much of the campaign has been put in the sourcebook, but even if that storyline was in there, it would not mean anything as these are different worlds in any case.

 To catch you up on the specifics:

• Vox Machina (heroes of Critical Role campaign 1) defeat Vecna with the assistance of Arkhan the Cruel
• Arkhan the Cruel (Joe Mangoniello's character he plays in every campaign he's in) previously featured in Force Grey, a canon Faerun live play show. This is the same Arkhan that later appeared in Critical Role creating an FR >> CR link
• Arkhan stole the Hand of Vecna, replacing his own hand with it and planeshifted away
• He then appears in Descent into Avernus, sporting the Hand of Vecna which is explicitly stated he acquired on Exandria (the plane of Critical Role)

So there is a canon connection from Faerun to Exandria, back to a Forgotten Realms set adventure featuring the Hand of Vecna acquired from the Exandrian proto-deity rather than the Oearth archlich.

 

Wow, thanks for the summary, I had bits and pieces of it but not the whole 5e picture.

Quote from ESTRELARIUS>>

But Arkham the Cruel showed up in Descent Into Avernus, which means things that happen on Exandria can afffect the rest of the multiverse.

 This does create a bit of a weird wrinkle, because Oearth and Toril are explicitly in the same plane (but different crystal spheres). Theoretically there could be two Vecna's, or Vecna from Oearth went on to Exandria where he started causing trouble. It could be that Vecna is more of a title or mantle that some liches and wizards take up, like Xanathar.

 

For me, if I look at the old Canon, the original Vecna has to be from Oerth, because of the whole lich + Kas + Sword of Kas = Vecna + Eye + Hand, if that makes sense. After that, Vecna has a complicated history even on Oerth, but also with ties to Ravenloft. The important part is that, at some time, he became a god, so we might be dealing with avatars all over the place... :)

 
Vecna's history with Kas and the Sword of Kas seems canon for Exandria as well since it was mentioned as such and Grog (Vox Machina) wielded the Sword of Kas in a fight against Vecna.

Maybe certain entities are so powerful and influential that their stories play out on multiple worlds over and over.

Quote from Davedamon >>

Maybe certain entities are so powerful and influential that their stories play out on multiple worlds over and over.

All of this has happened before, and it will all happen again. But this time it happened in London Exandria.

^MINOR SPOILERS FOR RIME OF THE FROST MAIDEN^

I'm sorry, I tried to keep this as spoiler free as possible. If you want to know the specifics, it's literally the biggest leak from the book. If you don't want to know, I here it is naught but a minor side-quest, do not worry .

it wouldn't be the first time deities or other entities crossed over into other settings. For example, the Abyssal Plague event was a multi-setting event with Tharizdun. Some deities, such as Lolth, Corellon, and others, are multispheric, meaning they exist in more than one plane (ie, setting), though the lore around them differs a bit for each setting, and their porfolios may vary somewhat. Matt Mercer has pulled elements from various settings and spun them to fit the lore of Exandria. Iirc, Vecna was originally from Oerth, but has since appeared in other settings, such as FR. I'm not too surprised Matt used him as the C1 BBEG.

Where is the eye of Vecna specifically in FR lore?

Quote from DRAGOLICH12 >>

Where is the eye of Vecna specifically in FR lore?

Unclear. In Critical Role, I believe it was destroyed (correct me if I'm wrong), so it may not exist anymore. 

Quote from Third_Sundering >>

Quote from DRAGOLICH12 >>

Where is the eye of Vecna specifically in FR lore?

Unclear. In Critical Role, I believe it was destroyed (correct me if I'm wrong), so it may not exist anymore. 

 I was just wondering because didn't it say in the dungeon master's guide every time you cast a spell from the eye of Vecna there is a 5% chance of Vecna tearing your soul from your body and using it as a puppet like thing. Does't that mean Vecna could come back from the dead.

Quote from Stormknight >>

Like any good villain, Vecna is always going to come back.

 Do you think that the next adventure could have Vecna in it?

Quote from DRAGOLICH12 >>

Quote from Stormknight >>

Like any good villain, Vecna is always going to come back.

 Do you think that the next adventure could have Vecna in it?

Many articles online that I have read say that a passing mention of him RotM may mean that Vecna, not just his eye and hand, is a true force in the forgotten realms. So there would be a precedent for it, but it is just speculation and Vecna is just as likely as a group of drow working to summon Lolth by capturing Eladrin or something. Actually, that last one sounds pretty good.

I wouldn't say there's two.  It's just a retcon.

They do it frequently.  Look at Corellon.  Originally he's a full on elf and the rest of the Seldarine are weaker but still his peers.  Lolth outright tried to lead a coalition of evil gods to kill him and take over.

Fast forward to MToF and Correlon is raw chaos changing form at whim and all the Seldarine are super powered elves he created.  Meanwhile Lolth's big crime is convincing elves to take a singular form.

I'd say use whichever Vecna history you like but that for 5e his CR ascent is canon.

I think there’s one Vecna who was originally from Oerth and became a god there, but he later incarnated on Exandria and possibly sent an avatar to Toril as well (or at least established a cult on Toril). He would not be the first deity to be worshipped or even manifest an avatar on more than one world. I haven’t read RotFM yet so idk about the time travel thing.

Yeah, that was my point earlier. Some deities exist on multiple planes (Lolth is found in both Greyhawk and FR, for example, though the lore is a bit different), so it's entirely possible that Vecna exists on multiple planes, though I don't think he was initially a multispheric deity. Matt used him in Exandria, but he has taken elements from various settings, anyway, and Vecna wasn't originally part of Toril. 

Right! I was thinking of Lolth. In Lolth’s case I think she began in the Feywild because that’s the home plane of the elves and spread to other spheres/ planes from there. (Or did they change that in MToF?) Vecna probably started on Oerth (where he was a regular lich  who became a god) and then later expanded to other worlds like Toril and Exandria.

I mean, it's known that Matt Mercer borrowed Vecna for his Exandria campaign, which like you said, a lot of people do.

However, a lot of people also enjoy doing deep dives into lore and canon, and with Matt's setting being brought into canon, it's fun to try and fan theory a reconciliation for what that means. Sure, you can handwave it away with "it's just conflicting lore, it doesn't matter, ignore it" and that's valid for a lot of people who aren't into lore and canon. I know for a fact the concept of canon is a contentious one in D&D, even more so than in other fandoms. But ultimately that's just kind of dismissing what people enjoy and doesn't really bring anything to the table as far as the conversation goes.

I ultimately like the notion that Vecna is akin to the other multi-world deities, a force that exists and manifests on different worlds differently, but always manifests in some way. Like how the Raven Queen is almost ever present, but endlessly varied, it seems to have a delightful symmetry that Vecna would be the same. As for the Hand and Eye, and the Sword of Kas, those artifacts too are likely fated to always exist somewhere, somewhen, although unlikely in multiple locations at once.

Quote from Davedamon >>

I mean, it's known that Matt Mercer borrowed Vecna for his Exandria campaign, which like you said, a lot of people do.

However, a lot of people also enjoy doing deep dives into lore and canon, and with Matt's setting being brought into canon, it's fun to try and fan theory a reconciliation for what that means. Sure, you can handwave it away with "it's just conflicting lore, it doesn't matter, ignore it" and that's valid for a lot of people who aren't into lore and canon. I know for a fact the concept of canon is a contentious one in D&D, even more so than in other fandoms. But ultimately that's just kind of dismissing what people enjoy and doesn't really bring anything to the table as far as the conversation goes.

I ultimately like the notion that Vecna is akin to the other multi-world deities, a force that exists and manifests on different worlds differently, but always manifests in some way. Like how the Raven Queen is almost ever present, but endlessly varied, it seems to have a delightful symmetry that Vecna would be the same. As for the Hand and Eye, and the Sword of Kas, those artifacts too are likely fated to always exist somewhere, somewhen, although unlikely in multiple locations at once.

 I actually do like tinkering with lore and canon.

I agree with your second paragraph but I think Vecna (and Kas) also have a definite origin point (Oerth).