He is fiercely competitive and will never settle for less than the number one spot, having a compulsive need to always strive for victory and also prove people who doubt him wrong. Katsuki is a crude, arrogant, short-tempered, and aggressive person, especially at the beginning of the series. Katsuki tends to come off as unheroic; this problematic behavior going all the way back to his early childhood days when he was known to bully a young, Quirkless, Izuku Midoriya. From MHA.Can make explosions