The best example is the manga Black Butler, where the teenage protagonist descends increasingly into evil after selling his soul to the devil to avenge his family, or something like Artemis Fowl which I read as a child but it would be preferable if it were more adult and more evil, or recently I've watched the show Killing Eve, where we end up rooting for the psychopathic serial killer Villainelle and wishing she and the policewoman protagonist would date. Anything like that. Even if it seems they are too evil a character to root for, but as long as it's that kind of story
by MorriganJade