Humans are social primates. We all want to belong, be part of something greater. Sometimes that greater is good, other times it’s not. The point is no one likes feeling they’re alone in the world. So, what happens when a person with a cloning quirk feels totally alone? Easy, you clone yourself.
Jin Bubagawara AKA Twice. His quirk, Double. His family, dead. It’s understandable he cloned himself. The committing crimes part, not so much. But, it’s not only feeling alone that drove Twice over the edge, but it was also, well, himself. Can you imagine not trusting yourself? Not in the I’m a failure sort of way. We all feel that at one time or another, more or less. I’m talking if you cloned yourself and that clone, that copy of you, tried to kill you. That itself would drive anyone crazy, but compound that with the yearning for companionship and you get…Twice.
All of that explains the strongest aspects of Twice’s personality, his insanity and his desire for family. It also explains why we’ve never seen him really get hurt. He was always holding back, afraid he was a clone and if he took too much damage he’d dissolve. Yikes! Twice had a lot on his plate, but everything’s okay now, right?