Tenya may look severe, but he's actually a very straightforward, earnest, intelligent and serious person. He tends to take everything very seriously, and because of this, he has a habit of jumping to conclusions, then enthusiastically speaking or acting based on said conclusions. He becomes a villain after becoming disillusioned about heroes and society as a whole, even going to the extremes of getting infected with a Vampire Quirk. He wants revenge, but a part of him still hopes to be saved.