Kurotsuchi Mayuri is a cruel, sadistic, unhinged mad scientist and it’s a doggone good thing he’s all of those things, because Soul Society needs someone who’s able to keep up with the weirdness and amorality of the Sternritter. If given enough time, Gigi could eventually turn every single captain, lieutenant, and foot soldier in the 13 Squads into zombies.
But Kurotsuchi doesn’t allow her that time, and has already developed countermeasures to her (his?) “killer app”. He starts by locking Zombie Hitsugaya into an “Endless Eight”-esque scenario: whenever he kills Mayuri, time for him resets to just before he kills him. After ten loops, Hitsugaya succumbs to paralysis, a side effect of the drug that messes with his perception of time.
At that point, it’s game over for Hitsugaya. Meanwhile, the newly glowed-up Byakuya easily handles Candice, NaNaNa, and, Robert (the Quincy with a gun). Shuuhei joins him, but to Byakuya’s surprise, he starts attacking him, as if he’s being controlled.
He is…by some guy named PePe whom the girls do not like, with good reason. Rather than turning people into corpses with his power like Gigi, he turns them into puppets who love him. He can do it to anyone or thing with a soul, resulting in Byakuya having to briefly fight Shuuhei with his bare hands while Shuuhei wields Senbonzakura.
Ultimately PePe is taken out of commission by Captains Rose and Muguruma, who while initially Gigi’s zombies, were converted into Kurotsuchi’s zombies when the blood of his resurrected Arrancar splattered on them. When Gigi can’t quite make heads or tails of his explanation, Kurotsuchi simply says All Her Zombies are Belong to Him, then she’s stabbed by a zanpakuto.
With things looking up for the Shinigami in Soul Society (at least those who are still alive and not zombies), we witness the destructive arrival of Yhwach, Uryuu and Haschwalth at the Royal Palace, where some much higher-level battles are sure to take place.