Like most teenagers who grow up secluded and isolated, Rex is overconfident, impulsive, and rebellious. He is quite headstrong, which according to Van Kleiss, he inherited from his mother, Violeta. He has a quick wit and is constantly making jokes, even in the direst of situations, often falling into sarcasm. However, when Rex needs to defend himself, he does not hold back. Aggressive and reckless, Rex prefers to smash anything that gets in his way, much to Providence's annoyance.