Everyone dies eventually. When they do, they have one of three options: Heaven, Hell, or Purgatory. The good go to Heaven, the bad to Hell, the redeemable to Purgatory.
If one goes to Heaven, they will live in their own personal paradise. If they're an especially good person, they will be given the option to become an Angel, serving as a heavenly soldier.
If one is a particularly rotten specimen, however, they will find themselves in the clutches of Hell. There, they are tortured for thousands of years until they either lose all trace of humanity and become a Daemon, or their energy fades to nothingness. Either way, the Torturers of Hell have done their job.
Purgatory, however, is a special place. If the Grand Council of Heaven, formed from the 5 Archangels and God, decides that a soul deserves a second chance, they are sent to Purgatory. There, they become an Idolion, something between an ordinary soul and an Angel. There, they fight against the Black Tide that is Daemonkind untill they either break, or are allowed into Heaven as an Angel.
It is in this last location that Valarian H. Vol first awoke...