Sōsuke Aizen
As the series progresses, however, Rukia is captured by the Soul Society's Soul Reaper military for giving her powers to Ichigo, and she is sentenced to death. Ichigo and his friends go to save her and are forced to fight against many of the Soul Society's Thirteen Court Guard Squads. Eventually, the fifth Squad Captain Sōsuke Aizen, the third Squad Captain Gin Ichimaru, and the ninth Squad Captain Kaname Tosen all defect from the Soul Society at the time of the rescue and start a plan, interrupting Ichigo's battles, to gain greater power with the arrancars, focusing the story with the main antagonist Sōsuke Aizen. In the manga, the last antagonist is Yhwach who is the son of Soul King and father of Quincy.