The best f2p azure fang team for wb, if you aim for high dps, not high damage per battle, is this one:

azure fang iruka clone

tenten gnw x x

Asuma wb x x

Talents: 41411 summon: ton ton

Mystery usage: round 1 iruka, round 2 skewering, round 3 tenten, round 4 iruka, skewering, asuma.

Main and tenten lands 80-85% of the damage and you need to retreat after round 4 and to resurrect with coupons asap.

mei can replace wb asuma and also give you a better overall damage per single fight but her animations will make the fight itself longer.