The Power Stone is a device built by the Rock Lords Magmar in his Stonehead fortress on Quartex.
Challenge of the GoBots cartoon
Magmar built the Power Stone to harness the power of his rivals' Power Scepters, adding them into the device while throwing the Rock Lords they belonged to in the Tumbler. After disposing of Talc he received the Power Sceptre previously belonging to Solitaire when the Renegades arrived from GoBotron, leading to Magmar making a fragile alliance with Cy-Kill. The two groups then marched on the Kingdom of Fossils and soon took the Scepter of Jaw Bone, allowing creation of the Ultra Sceptre, which popped out of the Power Stone. Unfortunately for Magmar, Cy-Kill immediately swiped it for himself. However, he was unable to control it, giving Leader-1 chance to destroy it.Battle of the Rock Lords