Torment Gigases were somewhere between "ouch" and "... wait, this actually isn't that bad". Setups:
Part I
Y'shtola (L99, Curaja R5/Wrath R4 - Dr. Mog's Teachings)
Quistis (L99, Mental Breakdown R4/Wrath R4 - Ace Striker)
Palom (L80, Ruinga R4/Chain Blizzaga R3 - Battleforged)
Cait Sith (L80, Heathen Frolic Sarabande R4/Multibreak R3 - Knight's Charge)
Papalymo (L99, Meteor R3/Chain Firaga R3 - Mako Might)
RW: Metamorphose
Full-kit Wrath'shtola is stupid good for Torments: SSII, Asylum and Aetherial Pulse cover so much mitigation I can't even fathom running another healer. Freeing up the Wall slot? Freeing up two slots otherwise grafted to Shellga and Protectga? AoE Curaga + Stoneskin effect alongside Medica and instant Curaja commands? Off -that- SB-gauge building setup? Sign me up please. She's like a swiss-army survival kit. Palom and Cait Sith cover AoE stackable debuffing (Palom also does double duty on crowd control alongside Potato, since this Torment's mobs like coming up in large numbers and those damned grenade bombs LOVE their MT physicals), Papalymo covers Hastega and buffing while being another crowd control monkey and Quistis does the bulk of the trash handling once her gauge picks up. The big problem in this dungeon is that you NEED to have all your mitigation (Wall+Shellga+Protectga) up BEFORE the Gigases show up, because the Thunder Gigas always opens with Thunderbolt, which scores 3k+ AoE damage THROUGH SHELLGA AND ELEM RESISTS, and they all start with fixed ATB. You will -never- put up SSII or SG before their turn unless you Powerchain into it beforehand (so, setup is necessary no matter what). A pre-emptive magic blink also helps, since the other two Gigases also always open with a Boulder. This said, the fight is very patterned, with zero RNG outside of who the Gigases target (they always use their magic on set turns), so if you can manage the bases, you're very much set. Deal with the Gigases one at a time, prioritize Thunder Gigas first (highest damage, lowest HP), leave Ice Gigas and his obnoxious perfect Blizzara counters for last. Quistis was clutch for downing Thunder Gigas quickly, too. EDIT: Nevermind, scored CM first try.
Setup!
Cid Mission
Minwu (L99, Ultra Cure R4/Protectga R3, Dr. Mog's Teachings)
Leon (L80, Full Charge R4/Lifesiphon R4, Lionheart)
Gordon (L80, Curaja R5/Full Break R3, Battleforged)
Leila (L80, Lifesiphon R4/Powerchain R3, Mako Might)
Josef (L80, Meteor Crush R3/Magic Breakdown R4, Ace Striker)
RW: SSII
I dove all of them for some stats off those cheap 3* motes and it wasn't a half-bad idea. In the end, everybody in my party had over 6000 HP (Minwu was the funniest, since I dropped him a Cat's Bell, propping him up to 7.1k HP, the highest in the party!). This said, the crux of the setup was really Minwu master race: the Burst kicks ass for handling the trash and the SSB is a hell of a panic button even now. In the same vein, instant Curaja from the Burst commands also rules. I thought I'd never use Josef's AoE boostga, but it was pretty great here, I used it to stack with HotE for great results against the Gigases and I had complete overkill SB for spamming my stuff (necessary, considering how hone-intensive Torment is). I ran out of SG juice by the time the Ice Gigas was alone, but, at that point, I was in no risk of losing even though I triggered a triple counter from him from Spell Sap XIV. Whoops, not triggering that bug again. Instant AoE Curaga to the rescue, though. No mastery under this setup, but that's what my first run was for.
Part II
Y'shtola (L99, Curaja R5/Wrath R4 - Dr. Mog's Teachings)
Quistis (L99, Protectga R3/Wrath R4 - Ace Striker)
Alphinaud (L99, Shellga R3/Valigarmanda R1 - Battleforged)
Cait Sith (L80, Heathen Frolic Sarabande R4/Multibreak R3 - Knight's Charge)
Celes (L99, Gaia's Cross R3/Saint Cross R3 - Mako Might)
RW: Ley Lines
More of the same, only with 100% more Valigarmanda+Alph BSB shenanigans being gloriously stupid against AoE fights. Seriously, a single Valigarmanda under the relevant boosts shaves off 80k~ HP from the fight total and Alph's summons also bypass Ice Gigas' counters. Celes was mostly nice for mitigating some of the trash mobs' offense. They ended up being -easier- than Part I mostly because Valigarmanda is so absurdly good when you can spam it.