The final Fragment is located near the Lighthouse in the Dead Dunes. To reach the Lighthouse, use the Cactuar Statue and teleport over to the Dry Floodlands area. Trek north from the ruins and you'll ...

Oracle Ascension Coins are a form of end-game currency that you can collect throughout the game. They are scattered across the world, so keep an eye out for any blue motes of light lingering around.