??

In order for Cain to live the other dude used the ukes life energy to revive and heal cains powers(as what that magic was and why the uke went into Cains mind) but if Cain continues to stay with the uke he will continue to take his life force and eventually killing him so he must leave to protect him. Cain is in love with him more so than just a master and door bond and thats why he will protect the uke even if it’s from himself. So Cain left and told the others to lie to him so he doesn’t chase after Cain. Hope that helps