Dnd Warlock Of Vecna. And the deathless wizard Fistandantalus. Vlaakith lich-queen of the githyanki.

While he was once considered the most powerful lich to dwell on that world over the ages he spent in undeath Vecna became maligned across the multiverse and was considered the scourge of all civilization. The Undead introduced in Van Richtens Guide to Ravenloft offers a gothic horror flair to the listThis is an ancient being that death has no power over such as Azalin Lord Soth and even Strahd von Zarovich himself. A demon lord of the Abyss Luz is referred to as The Old Wicked and revered for his heinous skills in oppression deceit and pain.
My group created a new world for our DD game using Dawn of Worlds and someone inserted the powerful Lich Vecna into our world.
The Fingers of Vecna consist mainly of thieves who engage in various forms of subterfuge. Vecna is usually depicted as a powerful magician resembling a desiccated corpse missing his left hand and eye and is one of the main reasons why so many evil. Im not entirely sure itd probably be better if your character doesnt. The DM may be no more powerful than a commoner in its own world but to our world its will is absolute.