Character Arc
Seto Kaiba is introduced as the cold, ruthless teenage CEO of the gaming giant KaibaCorp and the reigning duel champion before Yugi defeats him. Driven by an obsession with being the best and a deep-seated need for control, he initially views duels purely as contests of power and technology. His arrogance and his fixation on his three Blue-Eyes White Dragon cards mark him as Yugi's fiercest rival from the very first episode.
As the series progresses, Kaiba's harsh exterior is revealed to mask a fierce devotion to his younger brother Mokuba, whom he repeatedly risks everything to protect. He repurposes KaibaCorp's resources to build the high-tech Battle City tournament, partly to surpass Yugi and partly to prove his self-made strength. Though he rejects talk of ancient magic and destiny, the show steadily entangles him in the pharaoh's history through his apparent past life as the priest Seto.
By the later arcs, Kaiba remains defiantly rational and competitive even as supernatural forces swirl around him, refusing to fully accept his mystical connection to the pharaoh. His rivalry with Yugi matures from pure hostility into a grudging, almost respectful drive to claim a fair victory. While he never abandons his ambition, his unwavering loyalty to Mokuba and his code of self-reliance make him one of the most complex figures in the series.