Kaiou is the First Rashou and self-proclaimed Creator of the New Century—though "Demon Kaiou" is the name he prefers. He's the eldest of three brothers: his siblings Raou and Toki left Asura as children, but Kaiou stayed behind and became the country's strongest warrior. Fans often note his striking resemblance to Raou, minus the distinctive X-shaped scar cutting across his face.
What really defines Kaiou is his obsession with the main Hokuto bloodline. Years ago, Jukei forced him into a subordinate role under Hyou despite being the superior fighter—a slight he never got over. That resentment has festered ever since, making his hatred of Ken and the Hokuto line deeply personal.
Combat-wise, Kaiou is a serious threat. He's one of only two characters who've brutally overpowered Kenshirou on their first meeting (Souther being the other). To keep his overwhelming evil aura in check, he wears specially constructed armor that acts as a containment system. In the manga he's technically not the absolute final villain, but in the TV series, he stands as Kenshirou's ultimate opponent—a fitting endgame for the story's accumulated tensions.
Content compiled by AnimeList.moe from publicly available sources.