Board Thread:Naruto Discussions/@comment-34436445-20180627113230/@comment-734582-20180628160547

LegionZero wrote: @killman: can you really prove that though? Every other MS user has roughly the same limit on how many jutsu they can use. Every other MS user goes blind. Not Obito. Hashirama's cells empower the Sharingan considerably, to the point Koto had a massively reduced cooldown and even Izanagi (which normally only works for an instance) could be extended to 5 or so minutes.

Given those two things, i think it's fairly clear that Hashirama's cells are why Obito can spam his powers. I mean, Kakashi's MS eye goes blind and that's Obito's original eye, so clearly it's not Obito's natural power. and furthermore, Kakashi had made that eye nearly entirely blind yet when it was transplanted back to Obito, he could use it with no issues and had apparently perfect vision again.