Board Thread:Naruto Discussions/@comment-5054236-20150717003436/@comment-25093611-20150717185701

LegionZero wrote: Sasuke got it from Hagoromo. Just like Naruto got 6 Paths Sage Mode from Hagoromo. but: if sasuke got ashura chakra from so6p than that means that naruto got indra chakra, since he doesnt have rinnegan this means that this wasnt the case...

therefore, sasuke should have gained indra chakra which boosted his chakra pool immensly, and naruto got ashura chakra which allowed him (together with the bijuus) to gain SPSM,

and the missing part would be that "where did sasuke get ashura chakra?", and all we have is that kabuto healed him with the help of hashi cells ^_^