Responses

yeah from understanding this. knockers cannot be separated or spread out/ distributed from it's core part and still have a brain of its own, because of this, you're unable to spread the knocker to fellow family members. so when kahaku killed himself and the knocker he was able to fully remove it, unless the knocker took over, survived then made kahaku bang someone that looked like fushi.
If kahaku or whatever his name was died before he had kids then how tf did their hayase's bloodline continue?