Abacus - Twice
I feel like I should first say he's a villain in my hero academia. He's the one who cloned Dabi in the villain attack during the hero training arc :,)
In his past, be cloned himself over and over until he had a big team/group of himself. He was the king until his clones started claiming they were the real one. They eventually started all killing each other and even now, he has no idea if he is the real Twice. He suffers from dissociative personality disorder, constantly contradicting himself in his speech. When he does not wear his mask, he begins to 'split' showing strong self conflict.