It's impossible for a guy like him to always justify things. He should formulate a reverse drain skill and have the puppy gravely injure him, bare handedly. Then he can pass on everything to him, maybe his wits too.
It's starting to feel bad now. I don't think Kenji will die at the end if he stays as he'll likely be the most powerful being there. He's deciding for Kenji too much and slightly using it as justification to do the stuff he wants.