Satanic Coupler is a Stand bound to materials such as scrap, iron, steel and metal. With them it can create a huge, super powerful locomotive. Its appearance is similar to the diesel-lie locomotive EMD SD9, but it can change to adapt itself after sucking information from passengers via tentacles. This way Satanic Coupler can upgrade its speed and even create new optional features such as more comfortable seats and an efficient air system. It has no personality nor will.
Powerful Locomotive: It can create a train with high endurance, with the outer wall hard enough to only receive scratches after attacks from Silver Chariot's and Star Platinum's and the inner wall capable to parry and absorb any shock, the bottom of the train being its only weak spot. However, the structure itself can be damaged, even if not destroyed (e.g. By removing the tow hook, the wagons detach from the locomotive). In addition, the Stand can self-destruct after having miniaturized: this technique is used as a last resort to kill its enemies from inside their bodies. After its final upgrade, Satanic Coupler has been shown to be capable of running at more than 500 km/h indefinitely (as it can continuously create a line for the train to move) with the acceleration performance at the same level of a motorcycle, while its maneuverability is comparable to that of a car.
Power Up: Satanic Coupler can get a boost in power by reading the data present on the memory of its passengers in order to update itself to achieve the same performance of the most recent trains. Its appearance also changes according to the data (e.g. Because of Iggy believing that trains are monstrous things, the Stand got the appearance of a TGV, but with a more ferocious appearance, adopting a wild monster-machine look with stag beetle's jaws and thorns sprouting all over itself).