And another thing I forgot to mention was that Pein can revive any bodies that die in seconds, making it nearly impossible to kill all of them as long as one survives.
And yea, Shikamaru could find a weakness, but without any information, he ain't finding shit.
yea, Gai can go eight gates, but it doesn't last very long, as long as he can survive, Gai will die and Pein will survive.
For one, Naruto isn't gonna be there, and if he were there, he wouldn't do shit, except miss with his RasenShuriken OR hit Pein and kill a body, but blow his arm off in the process.
Listen, I'm not saying he's invincible, but we haven't seen him at 100% and when we do, it's gonna surprise everyone.
The person I see doing the most damage is Kakashi, as he can take out a few bodies FOR GOOD by sending them to a different dimension.
The only REAL flaw I see in Pein is if you TOTALLY destroy on of his bodies, but the only people who are capable of that are like...Shikamaru, Kakshi, and Naruto with the risk of loosing his arm.