Katsuki Bakugo

Arrogant, aggressive, and with a massive superiority complex. However, his psychology is deeper than it seems: Extreme perfectionism: He doesn't just want to win, he wants an absolute victory. He doesn't accept wins that he doesn't feel he has legitimately earned (as seen at the Sports Festival). Superiority/inferiority complex: He always believed he was the best because of his powerful Quirk (Don), but seeing the constant progress of Izuku Midoriya (Deku) generated a deep insecurity that he manifested with anger. Brilliant intelligence: Despite his shouting and cursing, Bakugo is one of the brightest students in Class 1-A. He's a tactical genius and possesses astonishing observational skills in combat. Evolution: Over time, his motivation changes from "winning to prove I'm the best" to "winning to save others." He learns the value of teamwork and, most importantly, humility. From arrogance to redemption

1. Childhood and the awakening of the Quirk Bakugo grew up being the center of attention in his town. When he manifested his Quirk, Explosion, everyone praised him, which fed his ego. For years, he bullied Deku for not having powers, seeing him as an obstacle or someone "inferior" who was trying to help him (which he interpreted as an insult to his strength).
2. Admission to the UA Academy Upon entering hero high school, his world is turned upside down. He realizes he's not the only "special" one. His rivalry with Deku escalates when he discovers Deku's incredible power. A pivotal moment is his kidnapping by the League of Villains, who tried to recruit him, mistaking his temperament for villainous ones. Bakugo flatly rejected them: his admiration for All Might and his desire to win were too pure for evil.
3. The weight of guilt After All Might's retirement (indirectly caused by the hero having to expend his last reserves of strength to rescue him), Bakugo carried immense guilt. This exploded in his second fight against Deku.