Steel Armor Diablos are crossover themed special individuals of Diablos with the appearance that are inspired by Alphonse Elric. Unlike their relatives, Steel Armor Diablos have grey shells and faces that look similar to Alphonse Elric's with one large conical horn on their middle foreheads.
Steel Armor Diablos have the same attacks like Diablos, but they have one special move. When digging in the ground, Steel Armor Diablos can create blue glowing circular patterns. After creating these, Steel Armor Diablos comes out of the ground to temporarily send pillars of rock standing while they slide on the ground before stopping.