And now both ultimates mastered!
Melusine was fairly basic with my standard shout team. I completely ignored her barrier mechanic by going all physical aside from a token fire skill for mastery. It was slightly rough because her immunities meant I couldn't use my usual stuff like banishing strike and 4* spellblades, but still not much of a problem.
Leviathan was a little more challenging, since with all the requirements on lightning, I couldn't fit my full suite of multiple layers of stacking mitigation. I ended up skipping protect, and putting squishier members like Ramza in the backrow with a harp. Still had some close calls from his physical hits, but no one died. It felt like Leviathan had more HP than usual for the final ultimate boss, but since he spends a lot of turns wasted in his water bubble thing, his outgoing damage wasn't severe.
Setup I used for Leviathan was:
Cloud -- Armor Break r4, Thundaga Strike r3 -- Fenrir BSB
Gilgamesh -- Banishing Strike r3, Lightning Jump r3 -- no SB
Agrias -- Life Siphon r3, Shellga r1 -- Cleansing Strike SB
Ramza -- Magic Breakdown r3, Full Break r1 -- Shout SB
Relm -- Curaga r3, Thundaga r3 -- Lakshimi SB
Roaming: Wall
Even though mastering the ultimates is a decent accomplishment, it still feels like I'm cheating by not doing it cid mode. I have a bunch of FF12 units leveled up, as well as a few FF12 soulbreaks, so I'm looking forward to our next FF12 event since I have a real shot at going cid mode for that.
Kind of wish I had recorded my omniscient fight. He actually gave me more trouble than both of the ultimates, lol.