Who do you think will win? now read and after make your choice.

Sasuke has no way of killing Kisame,

Chidori and Amatersu is useless.

Kisame doesn't need Samehada to absorb jutsu or chakra. He was shown to absorb some guy's chakra and heal and Bee's lightning that was uses to stab Kisame in the arm and instead of the lightning infused sword going through Kisame the Lightning was absorb. this mean he can absorb chidori or even rasengan,fire including Ama or any elemental chakra that pierces his skin? Just look at it he can absorb elemental jutsu's once it pierces his his skin he basicly can not be killed by element jutsu's.

Genjutsu can be broken

Kisame can fuse with Samehada to become a shark like monster capable of sensing, extremly fast swimming breathing underwater and absorbing chakra just by touching. Since he can sense chakra in this state he should be able to see through genjutsu. Manga states in this form he has no weakness. and Samehada can break him out by giving chakra.

Susanoo will not help much

He can absorb chakra with samehada, fusion form and great shark bullet and if Susanoo is underwater it will only hold Sasuke back.

Kisame can heal from anything Sasuke has

Samehada can feed Kisame chakra to replenish his own and even heal from it. Kisame natural durability is great as well surviving days in samehada, alive before healing after his torso was blown open by Bee's lariate and breaking out of Yamato's wood binding jutsu after taking Hirudora. Kisame states to Bee That he doesn't tire and never falls with his durability chakra and Samehada it's not hard to believe. if he is clipped by susanoo arrow he would just heal.

So how can Sasuke win?
I only got a chance to post 1 link because my laptop is acting funny I'll try to post the rest need be or read 470-471 it's all in there