Gilgamesh’s Dissidia 012[duodecim]: Final Fantasy 4th form is based on his look from Final Fantasy Type-0. The world wandering sword collector is decked out in Genbu armor.
Square Enix added the costume to the PlayStation Store, but if you want to buy it there you’re out of luck. Gilgamesh’s Genbu armor it’s only accessible via a product code given out at a Dissidia 012[duodecim]: Final Fantasy battle tournament. So far, Square Enix have not announced the outfit for North America.