i know this isnt a theory,but, i think if hinata and naruto had a child , ithink a new kekke genki could be born , now i know the ninetail fox isnt a kekke genki but what if somehow some of its chakra is transferred to during conception , this i think could mutate the byakugan to a much stronger kekke genki , dare i give it a name , how about i call it the kyubigan.i think if this happen the kyubigan would probably grant its user with the abilities of the ninetail fox without actually haveing the fox in them making them able to control its abilities much better than if they were a jinchuuriki, plus it gets the effects of byakugan , if this was to happen i think that it would defenitily be able to rival sharingan, ms , and possibly rinnegan. this could happen considering sharingan is from byakugan mutated from a demon (sobojo i think).