K - Season 2 Episode 12 Knuckle bump

Shiro, with his recovered memories as the Silver King reveals that his current body was once possessed by the new Colorless King (White Spirit Fox) who wanted to take over his original body to gain his power, but to no avail instead just possessing his body and not his powers. At that moment, his spirit had jumped to the Colorless King's recent body where he got amnesia. He uses his power to let the students of Ashinaka escape, at the same time cooperating with Kusanagi and Awashima to stop the two clansmen from fighting. Shiro asks Neko to become his first clansmen, and uses her power to find the Colorless King. After she successfully locates him, she passes out and Shiro leaves to confront the Colorless King.