I'm torn between Lee and Yamato. Lee is the more popular choice but I'm *almost* sure no one would put him in their PVP team outside of arena. Yamato on the other hand is very handy with 9 tails and group summon with his break.
First of all, OP you don't need that much for him. His books aren't in comparison to others since it's focused more on needing cursed ninjas on your team. The only one that is ok is the change in the Human experiment.