"Quand le bien-aimé reviendra" is the song heard in the HNL teaser which pointed out is an opera about a women named Nina. “Nina is in love with Germeuil but her father, Count Lindoro, favours another suitor. Also the ‘curse of the Baskervilles’ which is where Dustin’s little British monologue is from so it’s probably related to what happened with the Creel’s as well. Brenner’s aim was to “Expand the boundaries of the mind” after all and perhaps doing such to the greatest extent wouldn’t be able to be contained in the bounds of a human body. “Born a mortal wizard, he ascended to lichdom after assuming a mastery of the dark arts that no mortal had ever achieved.” Vecna’s mortal form being destroyed in the process as he ascended.
Using the Ritual of Seeding that was once responsible for bringing the Raven Queen into the pantheon, brought him as well, as the sole god on this side of the Divine Gate, and possible god-ruler of the Prime Material Plane” I wouldn’t be surprised if Vecna was previously a lab subject, specifically 001. “, was a powerful, mortal-born archlich who achieved godhood.” Unfortunately, failed to do so as he transported his Shadowfell city of Thar Amphala into the Prime Material world.