In the 1993 Reign of the Supermen! storyline, the alien tyrant Mongul and his forces destroy Coast City (Jordan's former home), murdering all of its seven million inhabitants, while Jordan was off world. Angered, he flies into Engine City and attacks Mongul, eventually knocking him out with Steel's hammer.[13] This leads into the Emerald Twilight arc, which sees Jordan using his power ring to recreate Coast City as an instrument in the process of overcoming his grief, and talking to ring-created versions of his old girlfriend and parents. After his ring's power expires, a projection of a Guardian appears and admonishes him for using the ring for personal gain and summons him to Oa (the homeworld of the Guardians and the Green Lantern Corps) for disciplinary action.[14] Angered at what he sees as the Guardians' ungrateful and callous behavior, Jordan absorbs the energy from the Guardian's projection, goes insane and attacks Oa to seize the full power of the Central Power Battery (the source of power for all Green Lanterns), defeating and severely injuring several members of the Green Lantern Corps in the process, taking their power rings as his own and leaving them to die in space.