Question: who replaced aizen as captain?
Answer: (later on when unohana died Isana took the position of Captain while Kiyone Kotetsu became the Lieutenant.) (He also succeeded Aizen after.) (After Hirako shinji Vanish there's one took the position of captain his name was Seigen Suzunami.) (Tetsuzaemon Iba succeeded Sajin Komamura's position after he died.)