Read it official: VIZ or MANGA Plus. Chapter 57 is the title people search when they want the betrayal. Samura has a deal with the Hishaku that looks like this: eliminate bearers, deliver blades, kill the Sword Master, then die with the ten. He cuts Uruha down at Senkutsuji. The temple collapses. Chihiro is still in the theater with Hiruhiko.
What the collapse is hiding
Suzaku can kill a Lifelong Contract and keep the person. Uruha walks later. The cut is a surgery that has to look like murder so Magatsumi’s knot does not spend the other bearers when a man is “saved.” Owl goes up over Japan. Hiruhiko signs Kumeyuri in the vacancy.
Arc: Sword Bearer. Essay on the support blade: Owl over Japan. Uruha’s innate art returns as Crimson Recital.