In Metroid Prime 2: Echoes, J-Stl was one of the 10 Keybearers. He was the mate of B-Stl, another Keybearer; this suggests that the Luminoth follow a matrimonial naming tradition similar to that found in many Earth cultures. Before it was collected by Samus Aran, J-Stl's Sky Temple Key was located in the Battleground area of the Dark Agon Wastes.