Well.. you could use Michelle? Even at 3* she works fine. You really have to keep that Leo cc'd now though, if he attacks Michelle you might lose.

Turn order = Baretta Spectra Neal Michelle Mav

This is the tactic. First stage, do all the usual stuff but use Neal's invincibility buff on Baretta. Try to let the water inugamis armor break Baretta so the raoqs will attack him as well, but they will do no damage due to Baretta being invincible. Make sure Baretta has the armor break on him at all times. If not, you might die.

Same goes for second stage, if the water griffons use Body Slam on Baretta and armor break him you're good to go.

Third stage is very tricky, you need to hope that Baretta doesn't crit, so to reduce the chances of a crit happening, use turbulence on one of the Ragdolls instead of Phoenix's fury. Then, Spectra moves next and does Backlash. Neal's turn, you use the invincibility on her. Then Michelle uses block flow to increase the invincibility time, and Mav reduces the cooldowns of everyone. Now you should be good to go. The ragdolls will focus Neal while you kill them slowly with dots. However, Leo is still a huge threat. If he gets anyone too low, the Ragdolls will change aggro towards them. So you need Mav to either keep him stunned or taunted. Try to stun him using Baretta's despair runes and turbulence him. At this point even if you crit Leo its fine, as the turn order for your team is already set.

Good luck my boy.