Reversal is the thirty fourth chapter of Haruko Ichikawa's manga Land of the Lustrous.
After stepping on top of the ominous black cloud that used to be a Lunarian vessel, Ghost Quartz begins to get dragged into a black hole above it by multiple Lunarian hands. Phosphophyllite cries out to ghost and extends out their alloy are in an attempt to help, but pauses for a moment and halts their movement. They instead stare intensely towards Kongo Sensei to see what he’s going to do about the situation. Phos witnesses him crack little chunks of himself off of his arm and launch it at the black hole that ghost was taken into. The whole vessel disappears and ghost falls out of the hole broken up into pieces.
Sensei then launches more of his pieces to destroy the remaining vessel in the southeast. Phos confronts him and asks what he just did, and Sensei explains that he usually uses more microscopic pieces of himself to destroy vessels, but he panicked in the moment. Surprised to hear this, Phos states that Sensei could run the risk of losing his memories using this technique, and he states that it’d be dangerous for anyone looking to imitate it and asks Phos to keep it a secret.
In the infirmary, Phos asks Rutile if they found any other fragments among the pieces of Ghost, but they confirm there weren’t any. Phos figures that Sensei must’ve picked them up himself while everyone else was searching around for pieces of ghost. They ask Rutile if they’ve ever had to treat Sensei before for anything, but Rutile answers that they’ve never needed to.
While phos ponders over the their information regarding Sensei’s connection to the Lunarians, Rutile finishes putting Ghost back together. Ghost turns to thank Phos, then states that they saw them stretching out their arm to help before being taken into the hole with the lunarians. Even though Ghost figures Sensei destroyed the vessel himself, it still made them happy Phos wanted to help. Rutile then takes Ghost to see Sensei. But Phos stays behind and mulls over the fact that they almost let a friend be taken just so they could see what Sensei was going to do, and how terrible of them it was.