I've used this lineup until I got Demon Fox, try use this : Main - Tobi - Hidan - Kakuzu
Talent : 33321
Summon : Ninja Cat
Main - Hidan - Oboro Clone
Kakuzu - Tobi - X
X - X - X

Round 1 : Use main mystery oh who you think gonna start the combo next round or their healer after their standard attack.
Round 2 : Use Hidan and Tobi's mystery on the victim. This will lead to 100% dead. If you think you have enough damage then use their mystery at 2 different targets. Also if enemy ninjas got tagged by Hidan on round 1, don't use his mystery on target who got tagged so Hidan can hit 2 targets at the same time.
Round 3 : KKZ's mystery. At this point the fight pretty much over.

Goodluck