By the time the Crystal Tower is reopened two centuries into the future, G'raha has partially fused with the tower to prolong his life as its keeper. He learns of the Eighth Umbral Calamity that claimed the life of the Warrior of Light and the Scions along with the endless conflict that followed. Acting on a hypothesis proposed by Cid, G'raha sends himself and the Crystal Tower to the First sometime after the Flood of Light occurred. Taking on the identity of the Crystal Exarch, G'raha establishes the Crystarium as a haven for the people of Lakeland.

G'raha attempts to summon the Warrior of Light to the First via the Calling, but ends up summoning the Scions instead. Due to the time difference, the Scions end up appearing years apart from each other. G'raha confides in Urianger Augurelt, telling him everything, and asking him to be his accomplice in a scheme to prevent the First's Umbral Calamity—with full knowledge that the negation of the Eighth Umbral Calamity would erase him and send the Scions back to their world fully restored.

When the Warrior of Light finally arrives on the First, G'raha, in the guise of the Crystal Exarch, acts as the Scions' guide and leader, directing their efforts in defeating the Lightwardens. When the final Lightwarden is defeated, G'raha reveals his true plan - to steal the light that the Warrior had absorbed from the Lightwardens. With it, he would transport himself and the Crystal Tower to the Dimensional Rift, where the light could be safely expunged, resulting in his death and the return of the Scions to the Source. His plan is thwarted by Emet-Selch, who had figured out his true identity and origin, and captures him.

When the Warrior of Light is preparing to battle Emet-Selch, G'raha uses his powers to summon heroes from other worlds to fight alongside them. After Emet-Selch's defeat, G'raha returns to the Crystarium, where he continues to aid the Scions in finding a way to return to the Source.