Bonus fights beaten.
Geryon was straight forward. Went in with a bunch of Instant Death resistance which ultimately wasn't necessary. Didn't use anything particularly special, just a lot of beat downs with Terra (Blizzaja/Thundaja wielder), Auron, Vaan, Yuna, and Tyro. Only notable thing is one reset as a result of targetting Auron before any mitigation and I think Dragoon's Determination killed him.
Cagnazzo...was a bitch. Really, really dumb fight, not sure how you're expected to do that without like 5 levels of mitigation or one of Indomintable Blade, Runic, or Grand Cross. His damage is crazy, he can pull water surging out of nowhere and screw you over, and blech. Luckily, I had Celes' SSB so just a case of getting things together.
My winning team was...
RW: Mighty Guard VIII (for go to Hastega and Heavy Regen; extra Haste to offset slow is nice too)
Some failed runs included:
Auron instead of Vaan using Lifesiphon/Venom Buster. At first I tried without any Dispel, so Ramza was Magic Breakdowning. Then realized I need Dispel, so gave Ramza Banishing Blade...oh wait, I need to lower Magic, that won't work, Magic Breakdown goes back on Ramza, and Celes gets Dispel since her damage is less meaningful than Terra's, and she's mostly there for extra Lightning and her SSB utility. That didn't really work since Ramza is covering 2 important aspects at once: Lightning damage and Magic Breakdown, and I can't have him really alternate.
Vaan subbed in because his SSB means only a little less damage than Auron's, and having someone who can Venom Buster AND Magic Breakdown while still having good damage would help a lot, since I can alternate between the two, and always keep him Magic Broken while trying for Poison. This frees up a slot for Ramza who can Banishing Blade, letting him do actual damage while dispelling, and Celes can try to sneak in Blizzara Strikes for quicker gauge building. Seems that was the right call, if my winning team wasn't an indicator.
This is, again, a dumb fight. If he opens with Water Surging, you're basically SOL since you're scrambling to get Lightning damage up quickly (or getting 3 layers minimum of mitigation) or he nukes you with big Water moves and you die. Worse is how you have to hit him with Ice damage while he's not surging OR using his shell, which can be a pain. It's just a really, really dumb fight and ultimately further emphasizes just how bad a realm FF4 stuff is as a whole. I think it's honestly the dumbest of the Ultimate(+)s thus far. Other contenders?
Bartandelus was dumb but only because of the idiotic requirement to bring Lightning AND Fang, meaning you're team options are incredibly limited, as are your approaches (want to use Mages to reflect attacks off? SCREW YOU FANG CAN'T DO THAT!) The fight itself felt like it wouldn't be so bad if you didn't care about mastery. Emperor was dumb because of that Starfall RNG req. Bahamut Sin...well, they basically admitted they screwed that one up when they redid the Turn Reqs for Ultimates because yeah, that was too complicated a fight in the turn limited provided for something like that.
The one saving grace about Cagnazzo is he's an Ultimate+ so it costs 1 Stamina.