Itachi vs Katakuri (both the most overrated characters in their respective verse imo)
Probably, Katakuri. How I see it, I think that the Haki can give to the user a protection against genjutsu. The haki don't have any relation with your senses, is pure will. We can see it in users like Fujitora, he don't see people and he even ask himself how is Luffy's face.
Itachi is a hard oponent anyway. But I think Katakuri has better stats and mobility. With his future vision, I can see him dodging every attack from Itachi, if Sasuke can dodge his amaterasu I don't see why Katakuri can't do the same.
Kisame vs Jinbei (sharks obviously)
It was hard to me, but I think JInbei has better ways to win this battle. I love Kisame but his sword won't going to work against a non-chakra user, while Jinbei can attack him in anymoment with his hand and gyojin karate. I don't that matters how much watter can Kisame use, a water battle between them is a useless batle for both... But Jinebi has Haki, is better in close combat and has enough stamina to fight for days even without chakra.
Sasori vs Doflamingo (string users)
Doflamingo stomps.
Hidan vs Killer (scythe users who laugh like maniacs)
Hidan only way to win, as always, is with his Jutsu. But if Killer is fast, he can end the combat in a second. He already fight against a enemy with a masochist technique and has feats cutting Kaido, he can make Hidan's body a lot of meat mass. Even when it wouldn't kill Hidan, he can end this easily.
A better fight for Hidan, could be Hawkings.
