The Two Scientists, Mayuri's Trap

Zommari survives Byakuya’s attack but Byakuya, having already discovered how to counter his ability to control others, quickly dispatches him. Mayuri initially seems unable to fight back against Szayel destroying his organs, but reveals that he has made himself immune to Szayel’s ability by replacing all the organs in his body after learning about the ability from bacteria he implanted in Uryu. He then activates his bankai, poisoning Szayel despite his efforts to make an antidote, then has it swallow Szayel.