I believe perfect sage mode is enough to beat nuggetofirst we ask ourselves:
is naruto rikudo mode chakra based?
is his godu dama chakra or not?
is his bijudama chakra or not?
if this is so, then we can ask ourselves why or how should this gudo dama or biju dma get past petra-path?
this seems unbelievable. But the resaon ist because Negato is unbelievable. Obito being Uchiha with Hashirama dna could barely use one Rennigan because he would lose himself. and Nagato used double Rennigan all his life time. He has Rikudo Senin eye power. and peter-path is absorbing all Ninjutsu in canon.
this is canon stuff and not fanboying.