Once Pein gets to Konoha searching for Naruto, what happens if Kakashi's the first ninja he battles?
I know, most of you would probably argue that Kakashi would get raped if he fought Pein one on one... a couple of things may actually make the fight interesting:
1. Pein and Kakashi are genius level ninja
2. Kakashi knows over 1000 jutsus vs Pein with his 6 bodies and 6 elements.
The key battle here revolves around Kakashi linking the Sharingan's genjutsu ability with MS as needed to confuse the Pein bodies. Pein is susceptible to powerful genjutsu if used well like was made clear in the Jiraiya fight.
3. Taijutsu, both are Godly.
Intelligent framing of any argument would be great because as we all know, power isn't always the most important part of Naruto fights, strategy/tactics is...