Thrawn

From personal experience, it's entirely possible to play a villainous character without having any kind of magic, power, ability, etc. All you need is a bit of cleverness and the ability to commit. I'm in agreement that you should avoid playing a character that's, as it's been put, "bad but not really". Anti-heroes are one of the biggest problems in the realm of 'evil' magics and CAs. If you want to play an evil character, be prepared to commit to actually commiting villanous acts, murder, betrayal, lying, etc. Even if it means doing so to characters belonging to your friends, or characters yours has built a relationship with. Also, importantly to me but not entirely necessary is to have some kind of motivation for being evil. The best villains in media are ones who have some kind of backstory or such that actually "justifies" (in their mind) their acts. I'd recommend steering clear of the cartoon villain aesthetic as well. Take your character seriously, and others will as well. If you want to discuss further, feel free to reach out to me on discord. bumblefina#0199  Best of luck in your roleplay.

there’s not enough room for the two of us

Thanks for the advice, everyone! The biggest problem is that most of my characters have been pretty bland so far/never do anything important, but a villain basically can't be bland, so it will be interesting trying to carve a niche like this.