Board Thread:Theories and Speculation/@comment-3001903-20150829033326/@comment-2140588-20150829130426

Seikatsu7 wrote: First of all, it is stated that Tsuchikages seem to hail from one family/clan, so Onoki possibly inherited Mu's abbilities. Umm.. No? It is highly hinted, but not "stated".

Same question could be applied for Kurotsuchi: Why didn't Onoki teach her "Dust Release" Or his (supposed) son? Most logical answer: There is either a restriction on who can learn it OR it requires a certain status to be taught.