The encounter with Hidan is a rather easy one - both your character(Kakuzu) and your enemy's are most effective at melee combat, meaning that, at least in theory, no one should have any advantage. One of the things you must be extra careful are Hidan's combo attacks - if he starts his several-hit attack, use your block and/or jump away from him. A single substitution and jumping behind his back won't do any good - the enemy will just turn back and continue his onslaught. If you are unable to dodge this attack, you will lose at least 1/3 of your health bar.
You will have a really big advantage over Hidan during this encounter - for the first time in Ninja Escapades, you will be accompanied by a companion (in this case - Orochimaru). You can use him in two ways - to activate Team Ultimate Jutsu (after you've filled your Storm Bar an information with the proper key combination will appear on the screen), which will deal a lot more damage than your "normal" ultimate jutsu, and it's a lot easier to apply, because it's very unlikely that the enemy will manage to stop you. The second application of your ally is to summon him/her on the battlefield, to do a single maneuver. It will not deal a lot of damage, but you can use it to link your attacks together, or to stop Hidan from approaching you when you are charging your chakra.
If you want to receive a bonus, finish the enemy by using your ultimate jutsu.