Got the apocalypse mastery. I ended up taking Vaan (lifesiphon, power breakdown, BSB) and Ramza (lifesiphon, fullbreak, BSB, shout, medica).
It was certainly a group effort win, as the team I went with played well, but I feel like I carried certain parts of the encounter! A few groups I joined would always lose on Enkidu stage because everyone completely ignored magic mitigation/breaks, so Enkidu would wreck everyone with his aoe wind nukes. Groups also rarely saved healing for the scripted aoe hp% nuke when Enkidu joined.
To fix that, I did Vaan (stacking magic breaks) to handle the Enkidu nukes, and I saved my Ramza's LB for the phase transition, and did Tailwind to help heal up his massive aoe nuke. From there, the party I was in took him down. We had three deaths because of the auto-kill RNG on zansuken (and no one brought raise), but still managed to win. Last 10% of Gilgamesh was edge of the seat, since the only people who weren't paralyzed the whole last bit were my Ramza and a BSB Luneth, so those two had to deal 10% on their own, and live through the rng death of 3 zansukens (which ended well enough).
Looking forward to next MP raid!