I agree, Seymour Flux was a pain in the ***. Took me about three tries to get it right.
As long as you could make it to Yunalesca's final form, you were fine. She just kept casting Demi which would halve your HP, but that was okay because a half of a half of a half of a half.... you'd get low, but you'd never quite to zero. And then you killed her.
Edited, Aug 28th 2013 12:22am by Catwho
Def. agree on Flux. I usually just ended up cheesing him with Aeon overdrives. 4 x 9999 + Bahamut's (with native BDL) 25,000 = 65,000 - about 5k away from a win. Huge post-OD delay was irrelevant, as they were dead on his first turn after summoning anyway. Toss in Wakka's attack reels, and gravy.
And the newer "hidden" bosses are definitely a step above the old ones - they expect
you to have basically broken the game, in order to have any chance against them. In FFVIII, I could beat Omega Weapon in 2 rounds with a bit of luck (2 x 12 second Duel's for Zell, a Lionheart proc for Squall), and getting that set up was maybe 75 hours of gametime. For Penance, I cleared any non-ability/+4 stat node from the whole of the sphere grid, replaced with enough of each to get to 255, then the rest were +HP nodes - minimum 150 hours. Still have nightmares about the monster arena! And Yiazmat - all 99's, ultimate gear etc. Not to mention a perfect run would be at least 2-2 1/2 hours long. Zodiark was a breeze in comparison - just the last 20% or so was a pain, with his physical & magical paling for 50 out of 60 seconds or so. Spam damage there, then rest/recovery.