Am I wrong for thinking Lord Flamingo has not been surpassed in evil yet for arc villains? Saturn comes second, but at the end of the day he is washed and a slave. I think if he could avoid killing in some situations he would, but there's really no choice when Imu is telling you to get something done. Doffy actively wanted to destroy the world. Honestly, Enel and Croco might be up there as well
The WG through Doffy kind of did it tbh they were profiting from the entire Doflamingo and Kaido underworld business deal by having weapons spread thorough the world.
There's no bigger evil than Im and his servants. Look what they did to Law's home city. Implied rape to the slaves etc.
They erased a country on a whim the moment they got access to fuel their ancient weapon. But tbf any villain would do to make an example of others if they had access to an ancient weapon idk.
Im and the Gorosei just give off this holy but unholy satanic vibe.
There's Blackbeard too who's just foul and shameless