I'm a P2P Player, but Exam 90 can be beat with for f2p ninjas:

Blaze, Tobi, Hinata, Kankuro.
3,3,3,2,1
With Summoning Shark.

x-x-x
Blaze-Tobi-Clone
Kankuro-Puppet-Hinata

Have hinata use her mystery 1st round; seal Sasori before he gets his puppets off with blaze mystery; I use tobi's ability right after on kisame. Should kill him or close to(either way you have acupunctured him no more mystery bomb) follow up by finishing sasori. Then the rest is a walk in the park.