Saiunkoku Monogatari Season 2 Episode 15 A Short Amount Of Time

As Shūrei and Ensei place the fake Dōshu and his men under arrest, he tries to buy time to make Shūrei step on the trap, but is surprised when he discovers that all the villagers are gone, and his men are replaced with men from the Sashu army, with Serian leading them. As Shūrei takes a step forward towards Senya, activating the trap, and is set immobile. But before the trap fully activates she is rescued by Riō, who tells fake Dōshu who is actually a boy called Ren that he was betrayed by his own people and doesn't have a body to go back to. It seems like Ren is actually Riō's relative. Eigetsu asks Kōrin and Ryūren to bring him near Kashin's body, before collapsing and to be replaced by Yōgetsu.