Board Thread:Theories and Speculation/@comment-28316199-20160723042954/@comment-10330822-20160723194326

I don't even know why this is a discussion. The anime production staff are doing this, not Kishimoto. There is no need to justify it, they are just doing whatever the hell they want. None of what that filler even showed was ever said to even to have happened, nor does it change anything we know about Indra or Asura.

Sasuke and Naruto didn't instinctively know Chidori or Rasengan because of their host status, they were taught the jutsu by completely different shinobi who have nothing to do with Indra or Asura. It's that simple.