Rimuru Tempest (That Time I Got Reincarnated as a Slime)

Rimuru is an eccentric and childish person by nature but this shouldn't be mistaken for immaturity and naivety. Underneath the surface Rimuru is constantly analyzing, planning, and weighing the pros and cons of his actions, taking the smart move in the long-term over more rash and emotional decisions. In stark contrast to this normally composed and calculative demeanor, he's absolutely ruthless when it comes to handling people who have angered him. He'll go as far as brutal torture and murder without batting an eye if he can get away with it and uses more subtle methods like intimidation and blackmail when he can't.