Messiah can produce 1 of 7 different pieces of equipment upon reaching level 98: Armor of Light, Shoes of Light, Aigis Legs v0, Athena Plate, Aura Doge Suit or the Omnipotent Orb. I needed 4 Armors/Shoes of Light and one of every other item in order to create the ultimate party, so I needed to buy Messiah at least 12 times. It ended up taking more than 20 times, since he produced Athena Plates, Doge Suits and Aigis Legs multiple times due to them having a higher drop rate than Shoes of Light and Omnipotent Orbs.
Sorry if that was confusing ^_^;