@Ninja Right now both Vera and the princess are assholes. Vera is slightly better because he has (had?) his friends, but when you think about it, he's an asshole towards everyone outside the gladiator group. He's also a scheming arrogant bitch. It's just that right now he's still dumb and innocent so he gets the short end of the stick a lot, all his schemes fail, and the more arrogant characters can humble him, but that might change soon. It's basically a perfect matchup of two scheming assholes right now.
The princess shouldn't change. She's perfect as the arrogant bitch she is. Her proper personal development path shouldn't be towards humility but towards directing that bitchiness to do good. She's basically the arrogant OP tactician shonen character, and she's already great that way.