Find and obtain the rare Final War Necklace.
Three parts needed here again: Mystery Part Un, Mystery Part Deux, Mystery Part Trois.
Once all three parts have been located. Take them to the research lab in Jibral Castle and speak to the research officer.
Mystery Part Un
Location: Alamaru Village - Before fighting Jeelala and entering the huge double doors, do a 180, go right and fall down the fall boards.
Mystery Part Deux
Location: Sea Cube, Deepest region, after defeating the Azure Abyssal Dragon, it is in one of the two chests beyond the doors ahead.
Mystery Part Trois
Location: ""Western Deserted Island". Need Mechat. Southwest corner of the map.