I managed to beat Ninja Exam 90 at Level 75 with 26k power with Lee (I am unsure if you can substitute regular Lee for this), Asuma (Wind Blades is better but regular Asuma works as well), and Guy. The goal was to take out Sasori on Round 1 with your standard attacks.

x x x
Lee Guy Main
Asuma x x

Skillset : 31121 White Snake Summon