Without Lunafreya, Starscourge's advancement accelerates and there is no cure for those infected with it. Daylight is quickly disappearing from the world. Noctis's goal shifts from simply saving his kingdom, to saving the world from daemons and darkness. He believes he can banish the daemons with the light of the Crystal. Starscourge is caused by daemons that expel substance from their bodies that blocks sunlight.
The imperial capital collapses as everyone becomes infected and begins to turn into a daemon. Those who can, flee the capital. An emergency is called and civilians are told to stay indoors. Dave Auburnbrie invites everyone in Eos to move to Lestallum whose power plant can provide light indefinitely due to drawing power from the active meteorite shards in the area.
When Noctis finds the Crystal deep inside Zegnautus Keep, he is absorbed inside it. He learns Ardyn Izunia is his immortal ancestor who once served the astrals but when saving people from daemons by absorbing them, corrupts his soul. Noctis learns he is the True King who can purge the world of Starscourge at the cost of his own life.
Noctis disappears for ten years, during which time darkness overwhelms Eos and it is overtaken by daemons.