Nullstone

During the Fifth Astral Era, the mages of Mhach had found a method to reach from their realm into The Void and commune with the beings there known as the Voidsent. These beings could be brought through to their realm and consigned to a pact to serve their needs. However, these Voidsent were devious and would often disobey and kill those who entered into a pact with them, and feed on their Aether. To counteract this, the Mhachi mages developed an arcane device known as the Nullstone. The Nullstone was capable of breaking the pact through magicks, and destroying the physical being a Voidsent has possessed. This would allow them to banish any Voidsent who would seek to do them harm, while also allowing them control over the beings, using them for war. When the Great Floods came, the Mhachi left this relic in the city to be hidden away, believing they had enough power to control the Voidsent that powered the Void Ark. This would prove to be a fatal mistake when the Voidsent Scathach broke free and killed everyone on board, effectively wiping out the Mhach civilization. Centuries later, Diabolos would attempt to use the power of this device to open a gate to the Void, but its plans were stopped by the Warrior of Light.