Well guys I just beat Phantom and Kurt Zisa on my 1st tries and Sephiroth on my 2nd. I'm lvl 74 with the Ultima Weapon, 2 Omega Arts and a Titan chain. I only used a couple of elixirs each fight. They were so very easy.
I had heard people found sephiroth hard at lvl 100. He was easy. The only time he caused me a problem was when the blighter said Sin Harvest right before I was about to kill him on my 1st try and I didn't hear it so I ended up dying.
I did have the game set on easy - but I'm guessing this doesn't affect the bosses? Or does it?
I was hoping for more of a challenege although Sephiroth was very cool.