Frayer

A transcendental being that observes the Simulation. They perceive the story through the different protagonists of the game, and controls them to make choices as they traverse across timelines.

The Nirvana Initiative was created to trick the Frayer into traversing time between the Past and Present 4 times each as Ryuki and the two Mizukis, creating 4 Xs and allowing Tokiko to reach Enlightenment and transcend the Simulation.