Sasuke vs. Pein? Seriously? The minds of fans...
Sasuke has nothing he's shown so far that can let him stand up to Pein. How is he gonna handle the non-stop summons from Animal Realm? How is he gonna completely obliterate Asura Realm with one attack, if at all possible? How will he get around Preta's jutsu-absorption abilities, along with dealing with the rest of the bodies. And we haven't even touched Tendou, whom Kishi referred to as being "violent and invincible" and who hasn't done much to disabuse us of that claim?
If Sasuke got owned by Killerbee, he would get owned to the tenth power against Pein. Even if he had all the info in the world.
Now, CS+Oro Sasuke, back when he had the snake powers, that opens up more possibilities. Summoning the large snakes to deal with Animal Realm's summons, using the medium-sized ones in conjunction with taijutsu to take out Preta, maybe using some high-powered Katons to take out Asura. But this is if Sasuke is on the absolute top of his freakin' game with the info that Naruto currently has on the bodies. And even with all that, I still say he'd lose in the end.
So this particular matchup is kinda moot if you ask me.
It always surprises me how dense and stupid the sasuke fans are to put him on a level comparable to J-man and even Itachi, let alone pein. And then they say something like "i am not a sasuke fan" . Yeah right
Sasuke would get his ass handed to him in a few seconds
but thats not true since Tsunade=Hokage
rank is not = power, its obviously seen from naruto post timeskip
here are some ideas for battles
post-time sakura vs zabuza
pre-time (Shikamaru vs. Shino)
I'm really not a Sasuke fan. However, the manga is constructed in such a way where Naruto and Sasuke are relatively equal in terms of overall power. It's a plot device which is pretty easy to understand and recognize.
I'd say Sasuke has the tools to defeat Pain but not the knowledge or skill to use them properly. Pain would win, I think. But it would be a closer fight than you'd think. Closer still, if Sasuke had summons like Naruto did.
Itachi was seriously exhausted and retreated right after using Tsukuyomi on Kakashi.
Sasuke's tsukuyomi on C was broken when Â went rampage on Sasuke, so if he's attacked and in trouble, his genjutsu will be broken.
Instant Tsukuyomi won't have any effect because it's based on causing much pain within a short amount of time. These realms don't feel pain, as Ibiki proved for us.
Using Tsukuyomi at all might be the worst mistake against Pain as there will instantly be five other bodies to overpower him.
I hate those arguments "XXX cannot be beaten in a normal fight", but for Pain this simply is true. As a rinnegan owner, he even is outside life and death as Konan says. He's on a different league than "ordinary" shinobi can get. He's even stronger than the Kyuubi if he doesn't face him in a totally drained-out state after atomic bombing a village with a single jutsu :P
However, Nagato would see whatever illusion that body would see, rendering that body useless for a while until another one rescues it.
It's funny, the six paths of Pain technique is probably the best anti-sharingan technique in existence, because as Chyio said, the best way to defeat is with more than one person.
The reason that Chiyo said that fighting the Sharingan is best when done with more then one person is because those other people can use their own chakra to break their comrades out of the gen-jutsu, like Sakura and Chiyo freed Naruto. Or they can act as decoys and purposely get trapped while the rest attack from the back like Naruto tried to do with his clones. But when all of those guys share a same active sense and the exact same chakra, all it takes is for one Pain to catch the gen-jutsu and it would immediately piggyback on the chakra being transmitted and make its way back to Nagato and shut down the other bodies while trapping Nagato in the gen-jutsu. It absolutely becomes a worst case scenario to fight a proficient gen-jutsu user. Gen-jutsu was Nagato's weakness, which is why he immediately got rid of Fukasaku before he could cast his sound gen-jutsu.
If/ when we get to see the resurrected Nagato fight I highly doubt that we'll see his puppets again, if anything we'll get to see the real Nagato spamming different elemental attacks and a few from the big statue as well ( forget it's name, gedo something :/ ). Those puppets have to be prepared in advance and have probably been disposed of by now by Konan.