Any character is fine.
The rare ninjas I have are: Mifune, Gakido, Ningendo, Chikushodo, Sage Naruto, Killer B, Gaara Kazekage, Kinkaku
I have pretty much all common ninjas, all ninjas I can recruit in arena/ranked/survival battles. on top of that I have GNW Shino, GNW Tenten, GNW Sai and GNW Ino.
Please help me, no clue what to do D: