This is such a weird IP to pick, and an even weirder choice of killer. It feels really weird to cram a lich-turned-god into the same gameplay mechanics as a slasher movie killer, esspecially over many more iconic, recognizable, and unique character/monster designs.
I'm not a D&D fan in the slightest, but I would have thought something like a Mindflayer or some sort of lesser beholder would be more fitting, more inconic to D&D and more distinct from the other DBD killers.
On the D&D side, the final big adventure is releasing for D&D now before they refresh the rules starting in autumn. That adventure is high level and the main antagonist is Vecna, with him effectively having lieutenants of many of the other popular villains.
This isn't just a D&D tie in, it's an ad for Vecna: Eve of Ruin.
In bg3 the big bad were 3 people that controlled an elder brain, which is a mindflayer "parent" of sorts. Which then frees itself and gets empowered by the nether crown becoming a netherbrain. It's very much about using the mindflayer technology to control people by halting their transformation into mind flayers so that they can act as spies, but the moment the nether brain got free it became a fight against it and a lot of mind flayers.
That's not what sort of means. Sort of means that they did not use them fully, and that's just not true when there's not only several of them, but they are a major plot point.
Would you say "there's violence (sort of)"? No, there's lots of violence, no "sort of" involved.
But the statement was in response to using mindflayers as the main antagonist. Or the big bad. Which we both agree, they were not. So whilst they were a big part of the plot they were not the main bad guy and so....
To circle back
They were used in bg3 (sort of)
Edit: also sort of doesnt mean "they didnt use them fully" it means they weren't the big bad but they were very closely linked. The big bad was the netherbrain alongsode gortash. Not the mind flayers. You can look that up.
Wgen the final boss is a mindflayer(s) then come back to me and let me know. Until then, dont tell me what i meant when i said sort of....
I just used those two because I figured they'd want iconic D&D monsters, whereas Vecna, esspecially after taking away the godhood and magic elements, is just a fairly generic undead skeleton.
I take any good things back that I said about the game. I thought it was going to be a 5e game or something but it's just a cash grab using the licensing of DND.