One of the best JRPG fights I've had in years.
It demands no less than perfection from you: The best gear, the best spells, the best techs, and so on. Better not having slacked off on exploration.
Absolutely brutal on phase 2 (if you don't use Dark Magic like I did), the boss will put you on your knees until you figure out how to approach the fight... and pray to RNJesus a lil' bit.
A super satisfying boss to overcome on a first playthrough in Hard, and a banger OST to listen to while the boss smacks your face.

It definitely has this feeling of epic RPG bosses from the old days. I'll be remembering this one.