Still, I finally beat him.
I think the 50 minute trick would have worked if I had more hi-ethers. I only had ~19 of them. Otherwise I just tried to syphon off my berserked characters.
FYI, with only 1 masamune, 2 YDBs, 1 brave suit, 1 Staff of Magi, and 2 Lordly Robes, the 50 minute trick works pretty well for the first 65-75% of Yiazmat’s 50 million HP. But once he started spamming the rakes, death strikes, and physical attacks that may cause instant death, I kept only 1 berserker in the fight and 2 rev+decoy aides, and ran out to save/recharge after every bar of life.
Still, I got the bastard.
(I’m not even doing it for the wyrmhero blade. I’m just nuts.)
And then you get him down into the red, and Yiazmat stops fucking around. His attacks combo like crazy and will either insta-death or just kill you proper; even with Bubble. I completely stopped casting Curaga and started casting Arise. My first three crystal breaks were all on his last three bars of health. That fight is brutal, though it would be considerably less so if FFXII had Safety Bits or something similar.
But then he whipped out his critical health on my ass and almost wiped me off the face of the earth. His twelve hit combo really crippled me, but I got him good in the end