@Darkmeep
2 months late to replying on this. hell yeah.
He never intended to steal Fushi's forms. He merely wanted Fushi to rest. The Knocker either A)Granted his wish in a diabolical form, or B)Took advantage of the situation. Either way, the result is Kahak became terrified and tried cutting his arm off, hence this whole situation as to retrieving the knocker once again. He also says it himself in chapter 103, he wants Fushi to retain his humanity and protect him. His methods personally are definitely.... not the best though, and he doesn't exactly help his case when he lashes out against his comrades.