Liches in general are powerful and unpleasant in equal measure, but even by their usual high standards Vecna is noteworthy. He actually ascended to godhood at one point, although—as is so often the way with the obsessive pursuit of power—it didn't work out entirely well for him.
Vecna is perhaps not quite as powerful in Dead by Daylight as he is amongst the Planes, though, with just four spells at hand: Naturally, a new killer demands balance with a new survivor, and in this case there are two: The bards Aestri Yazr, an elf, and Baermar Uraz, a human. My first reaction was why a bard, but in hindsight it makes sense: Bards aren't likely to start too many fights and unlike, say, an angry dwarf with an axe, they're typically not going to be too inclined to try their luck throwing hands with a lich.
Finally, I have another game about being a freaky little nasty guy trapped in an otherworldly hell dimension to look forward to