Location: This quest can be found in Octagonia (after beating the main story quest here).
Objective: Find Xero the Shadow and Get His Autograph
To find Xero, make your way to the Octagonia – Tournament Reception and turn right. You will head past the angel statue (used to save) and up a flight of stairs. Take the stairs on the right up another flight to find yourself at a dead end. Climb the right wall to reach a balcony overlooking the giant statue in the center of town. Follow the path to the end where you will find Xero near a pillar. Talk with him to receive his autograph, then head back to the boy in front of the orphanage. Talk with him and hand over the autograph to complete the quest.
Reward: Mini Medal