The Imp's True Face - S1.E21

Kurogane tells Syaoran to blindfold himself and walk back to The Cat's Eye and that he can't take the blindfold off until he can recognize presences. While training, Syaoran notices that Oni have the presence of something which isn't alive. Kurogane and Fay leave Sakura at The Cat's Eye and go to talk to the lady that saw the new type of Oni. They find out that the Oni is created for the purpose of hunting. The new Oni seems to have Sakura's feather, and reveals himself to be Seishirō.