There are many tropes you can access as a villain. There's the Evil Overlord trope. There's the Evil Senator/Nobleman Trope. If you want an unconventional villain, use Valentine from [u][i]Kingsman: The Secret Service[/i][/u] as an example. Hilariously dark in that while he is trying to kill people, the actual act of violence and bloodshed disgusts and repels him to the point where he upchucks at the sight of blood.

There's the psycho killer trope. There's the evil mad scientist trope. There's the Purge Evil at all costs/Catastrophic Ends justify the means trope. Return of the Evil god/entity trope.

Yeah... there's a lot there.