been throwing every 5 mythril i get at the Celes banner. just single pulled Terra's Tiara, which makes me pretty happy despite not being for my waifu.
hadn't finished the Ultros CM yet. kept getting super close, but couldn't quite topple him over at the end. that Tiara was just the tipping point i needed. it is 4 fire hits + En-Fire. gave Terra Ace Striker RM... she ate Ultros #2 alive with his fire vulnerability, then was able to dole out plenty of damage for the rest of the fight with R4 Firaja and that En-Fire active the whole time.
that was the only unique SB i brought to the fight, tho i do have really good generic FF6 synergy.
full team:
Celes - Power Break + Banishing Strike - Sword DMG+
Setzer - Full Break + Magic Breakdown - Dragoon's Determination
Terra - Drainga + Firaja - Ace Striker
Mog - Curaja + Protectga - Heal+, non-RS shared Medica rod
Relm - Curaga + Diaga - Holy DMG+ RM, RS Holy DMG+ rod, non-RS shared Medica bracer
Mighty Guard VIII RW
Celes' default SB (RES+) was pretty invaluable too, made leaving RW Wall out not hurt so bad.