Pein had near full intel on the MS sharingan anyways, full intel only helps him with the other techniques Sasuke has. So, Sasuke has an advantage over some of the paths. And with intel, Pein is a severely reduced threat. If the Deva Path can work right away and there isn't a waiting period, Sasuke is in trouble.
What could happen is either the Deva Path pulling Sasuke in and having the Asura then attack him, but a quick Susano'o would negate this. What COULD be the biggest problem and a potential game ender is Shinra Tensei.
Yes, Shinra Tensei. If Pein were to use it on a slightly larger scale, as he did against the toads, Sasuke is most likely severely injured or incapable of continuing the battle. It threw the toads out of the crater, out of the village, and into the forest. Breaking their bones.
This WILL be a huge issue for Pein, and the easiest win. While Pein is a terribly powerful foe, if you happen to be quick enough in taking out the paths, the threat is reduced. Not to mention that intel is key against Pein. I would go so far as to say Sasuke would lose to Pein, mid to high diff when lacking intel. And MS Sasuke I would put below Pein.
But, in this current scenario I can see Sasuke coming out on top. The chances of Deva getting into this range and not being attacked by some Susano'o-offensive weapon or attack is slim. The only thing that can get Deva to a close enough range to use the slightly stronger Shinra Tensei would be both sacrificing paths and several summons.
And, Sasuke here will be plotting which paths are the most deadly. I personally think he will go for the Preta Path first and charge it in close range. The ability to rid ninjutsu useless is the greatest threat to Sasuke. The Asura could defend against the Preta Path in the close range combat, and has a chance of overwhelming Sasuke.
IF the Asura Path is in close enough range for the Preta to cover him from Sasuke's ninjutsu. If not, then both Asura and Preta Paths are destroyed. And Sasuke then aims for the Naraka Path with a Susano'o Arrow. Which may or may not be countered with one of the many summons throw infront of him to block the attack.
The animal summons are only useful as distractions, and an extra few eyes on the battlefield though. Sasuke lacks Naruto's strength to deal with them, yes. But Amaterasu or a Susano'o arrow will leave any path unable to continue. Even Cerberus.
The Human path is almost always useless in combat, which is why Nagato so readily sacrificed it for the Animal Path. So, the Human Path, Asura Path, and Preta Path are dead. The Naraka Path is going to be covered as much as possible, and the human path will provide issues. If the Deva Path could sneak into close range of Sasuke and his Susano'o without much notice to him being there, he can win here.
But, that is somewhat unlikely. The animal summons that would distract Sasuke won't survive long enough for this to happen. The Naraka Path would probably fall victim to Amaterasu, the Animal Path a Susano'o arrow. And the Deva Path would probably survive a little longer. Thanks to his agility and and Shinra/Bansho Tensei/Tenin. But Sasuke is going to eventually get an attack in.
So, this scenario? EMS Sasuke mid to high diff. An MS Sasuke would suffer far too many withdraws that would create openings here. So, I used EMS Sasuke to make it fair. Not sure if that was in the OP or not..
