He knew about the rinnegan. He's the one that trained Nagato on how to use it. You mean he didnt know about the 6 paths technique?well genjutsu wouldnt work on jaraia because of the toads on his arms. Ameratzu wouldnt work because he has a wide range of defence jutsu. PS might be a viable option. Jarayia was the only person in the nv that took on the rinnigan without knowing a single thing about it and won for the most part. i still say sasuke but not as easy as you guys would think. Sasuke would definately get banged up a bit
Just for knowing doesn't mean he can beat it. Anyone can see and know rinnegans tech, even konohamaru can know it too, but doesn't mean they can winHe knew about the rinnegan. He's the one that trained Nagato on how to use it. You mean he didnt know about the 6 paths technique?