better: you turn a hero into a villain but midway through their villainous arc, they realise they’ve become a villain and descend into madness, losing a grip on the ideas of good an evil and descending into complete insanity, degrading them to making extremely risky bargains which could tie them to some extremely dark and evil sources that could ‘grant them the power to right things’ when instead they’re being tricked into becoming something much worse.

hero, villain, madman, psychopath.