Ok so I read to page 8 and quit because I knew the Kakashi fans would be screamin g their heads off about the sharingan, kamui, and raikiri.
Well obviously what those kakashi fans don't get is that this is not a battle kakashi can win. You can't kill Oro unless you have more chakra than him (He doesn't, don't argue this because if you do I will scream and flood your profile with databook pages and insults),
seal him,
or pretty much disintegrate him to the point where he couldn't regenerate. (something like Amaterasu or TBB might work but Amaterasu would only work if he sat there and didn't cut off whatever was on fire)
Why you ask are these the only ways to kill him? Because as long as Oro has chakra he can regenerate!!! From any wound, honestly kamui wouldn't do anything to him as he can regrow whatever is lost. So that leads to Kakashi just wasting a huge amount of his chakra on nothing. And the same goes for any physical attack Kakashi does to Oro, plus Oro is faster and stronger than Kakashi so I don't really see him beating him in a taijutsu fight. And even though it wouldn't hurt Oro in any way, if kakashi was to try going underground well we saw when Sai went underground and how Orochimaru knew he was there.
EDIT: You kakashi fans should especially try and read this part. Sasuke never killed Oro and in fact he didn't ever beat him, what was unique about that fight was that Oro tried to take over Sasuke's body and Sasuke used sharingan to reverse it thus why he absorbed Orochimaru. Unless Oro tried to take over kakashi's body (which he wouldn't because that would be a stupid move) then kakashi would never have the same chance Sasuke did.
Oh and for the rest of the sharingan and kakashi fans I'm going to say this Sasuke would never have beaten Orochimaru in a fight. Had Oro actually wanted to kill Sasuke instead of trying to take over his body then Sasuke would be dead right now and Oro would be in a weaker body somewhere. Oro wanted the sharingan and apparently was willing to risk his life for it.