To unlock the Aeon Cup, capture the Flame Dragon, Flan Blanco, Mycotoxin, Machina Striker, Jumbo Cactuar, Critical Bug, Azi Dahaka, Aranea. Complete the Fiend Tales by leveling them five times, win the cup three times to score Peerless, the second best Garment Grid in the game! Bahamut has a lot of HP. I gave up some accessories to feed the Chocobo a big boost in stats. Lucky, you can claim the rare accessories back from different cups.