Board Thread:Theories and Speculation/@comment-27924662-20160817160245/@comment-1872728-20160830051258

@UltimaDude @GreatestSin Hagoromo gifted Naruto and Sasuke their SPSM and Rinnegan respectively via activation after receiving SPSC and SPC respectively from Hagoromo. After activation, they could generate the chakra by themselves.

It's possible that the Hashi Cells in Orochimaru/Kabuto's possession no longer contain Asura's chakra. Plus, both the SPSM and Rinnegan are abilities of Hagoromo, so it's not a surprise that they would work similarly if not the same way.

According to Madara, not having both his Rinnegan doesn't stop him from using Preta Path, so I'm guessing once the person awakens the Rinnegan, they'll gain the ability to produce SPC even without the Rinnegan.

What I believe, is that whatever contains SPSC or SPC can potentially block out IT light. They are both Hagoromo's chakra, so if one of them works, I don't see why the other wouldn't. The Rinnegan is the only thing that is 'shown to be able to resist IT, and Black Zetsu doesn't know the full extent of SPSM's abilities, so his words aren't definite.