polarspaz:

So the night before the group heads to Altissia to meet up with Luna, Noctis dreams of his destined future. A dream of death, sadness, and pain only to violently wake up to see a stranger in his room.

Diabolos, King of Nightmares, sits in a chair across from him, guised as a human. He tells Noctis that he is an Astral, just like Titan and Leviathan, however he was banished into darkness long ago by Bahamut.

Diabolos had sided with several other Astrals under the command of Odin, wishing to abolish such things as fate and prophecy, however a war ensued with Bahamut and they were sealed away for thousands of years.

But now they have broken free and Diabolos proposes a new path for Noctis to take. To bring about a world that isn’t neither light or dark, but something new altogether. 

Desperate to stop the ill fate of those he loves, Noctis agrees and abolishes the old pacts he has made in order to forge new ones with the forbidden Astrals, allowing Diabolos to guide him into the now unknown future.