You have Bartz USB and his triplecast LMR. Finish diving him, hone Engulfing Twinstrike, and you have all the Water DPS you need already i think.
His BSB2 isn't bad, but it's not great either.
Btw Falk, thank you for sharing your set up for Mist Dragon. I finished farming Shadow Dragon and finally went back to Mist Dragon today, got an easy 27s clear with the following set up, tweaked a bit from yours:
Relm, Shellga/Curada, USB, Ace Striker
Jihl, Memento/Dark Zone, BSB, Gathering Storm
Raines, Memento/unused, BSB, Scholar's Boon
Larsa, Wrath/Entrust, BSB, MM
Tyro, Magic Lure (forgot this doesn't work on WHT spells ;_
/Entrust, Wall, DMT
Magicite: Shadow Dragon (imperil increases Raines' damage by like 1k per hit, plus Shadow Dragon itself does some decent damage)
After realizing Magic Lure doesn't work i switched Tyro to Faith/Dire Heal, should get an even faster clear next time.
Mist Dragon is so much easier than Shadow Dragon, it was a relief fighting her. Shadow is such RNG bullshit. If Raines doesn't dualcast first cmd1 i have to eat Black Fang, if it doesn't hit a healer, reset. Even if i avoid Black Fang or it hits a healer, if Shadow uses Frostblast, or just spams too many AOE in a row, reset. One clear today took an hour of resets until RNG went my way. I'm not looking forward to farming this asshole for Major Darks once i'm done getting all the other magicites L.80 cap broken.