Dissidia 012: Duodecim Final Fantasy

Purchase Dissidia 012: Duodecim [prologus] Final Fantasy from the PSN store. When at the installation screen, download the file with the the data for Aerith to your Memory Stick. Start Dissidia 012: Duodecim Final Fantasy and Aerith will be a selectable assist character.

Successfully complete Main Scenario 012.

Finish Main Scenario 000 to unlock secret character Desperado Chaos.

Finish Report 08 (6) with Bartz to unlock secret character Gilgamesh.

Finish Report 08 (2) with Shantotto to unlock secret character Prishe.

During the tutorial you will be asked by the Moogle if you have already mastered Dissidia. Answer "Yes" to battle against a level 130 Feral Chaos with a level 1 Lightning. If defeat it, it will be automatically unlocked in Free Battle mode.

Successfully complete the game. An option to play the original Dissidia story will appear at the "Story Selection" screen.