Seeking any and all Atma tips

I beat Brave New World in version 1.8.5 or 1.8.6 and am finally revisiting, and I am surprisingly stuck on Atma. Maybe I got lucky three years ago, or maybe I'm unlucky now, or maybe Atma's design has changed that much. I don't know. But I'm looking for any and all advice, no spoiler unwelcome (I still remembered the unlockme password, even) and no basic tip too condescending. I've been running Setzer for heals, Strago for Blowfish, Gau for Brainpan (Blowfish/Rerise), and of course Shadow. I'm good with the battle until the Mind Blasts come out, at which point I have a really hard time keeping up with anything that's happening; I tread water until I get a bad RNG break and then I can't even tread water. I will admit I have a personal problem with regenerating bosses. I hate them and they get my blood up, and this reduces my willingness to engage, iterate, and develop strategies. It is what it is.

Favorite teams? Most reliable strategies? Key things I may be missing?

Atma is weak to Ice, so Ice 2 from Strago might get you some better output than Blow Fish.

That is a bit of a tough team with no Life casters and two squishies. If you're super pro with Slots, Jackpot (777) is a weak revive though. Definitely keep up on the Rerise, and take note if Purge brings it down.

For Mind Blast, equip status protection relics to prevent the worst effects. An Amulet on Setzer might be advisable to ensure you have a healer who won't lose control.

If you still can't make it work with this team, try tapping in Celes instead of Gau. Life, Rerise, Ice 2, Remedy, Slow, Float and Dispel are all crucial tools for this fight, and Runic can be nice if you can fit it in around everything else (timing is key though, watch out Strago's casts!). Mog for Setzer could allow for Harvester from Forest Suite to deal with a bad Mind Blast roll (go ahead and Spirit Stone + Amulet him to ensure you don't lose him), and Earth Blues is a solid option the rest of the time. Or Ice Rod proc fishing from the front row.

Good luck!

In a word, Dispel

Yes, this was good advice. Thank you. I switched parties (stuck with Setzer but swapped out Gau for Celes and Strago for Cyan), prioritized Dispel and Slow, bought more status accessories, and had no problems with my first attempt after that. I didn't religiously keep up Rerise (though I did cast Seraph after the second phase started) but with a tankier team and Atma's reduced offense it worked out. Onward!

Dispel is definitely a must.  

I found that if you didn't buy the necessary items for Shadow, running double healing daggers makes him an extremely viable healer for the fight.  

I couldn't make Shadow work with all of the counters on Floating Continent in general (along with his non-existent esper choices at that point for spells), and decided his speed works well for all the ally shank