Rain of Blood Incident

The Rain of Blood Incident (血液野雨, Ketsueki no Ame) was an infamous duel between former Seventh Division Captain, Kai Nageki, and his predecessor, Kenshin Tokugawa, for the captaincy of their squad. While trial by battle is a legal avenue to the rank of captain, it is looked down upon by many within the Gotei 13 and Seireitei itself, especially when the challenger is the captain's subordinate. The duel is referred to as the Rain of Blood Incident due to the gruesome nature of the battle, where then-captain Kenshin was supposedly obliterated by his Lieutenant, Kai, according to eye witnesses—moreover because it was a rainy day when the duel transpired. The battle left the division's barracks in ruin and the damage even spilled over into the surrounding grounds. Kenshin Tokugawa, head of his clan, was slain on a rainy day before his subordinates in a battle sparked by the shinigami's abuse of Rukongai residents. The battle resulted in a new seventh division captain, the decline of the Tokugawa clan, uproar throughout the streets of Seireitei, fame for a man that tried to keep a low profile when possible, and a mark left in the history books of the Soul Society.

Trivia

 * Kai was never pushed to the point where bankai was necessary during the duration of the fight.