"John. This is your final power. Precognition. Don't you see? The ability to know what is going to happen. And, if you know what is going to happen, then you can stop it."
Often considered only a vicious trap that preys on the fears of its victims, the Vattic Trap harbors an important secret.
When you sleep, your soul briefly returns to the place where it was created/goes to when it dies, and seeks nourishment. Everybody's soul is created with a little link (or you could say a greater entity calls it back) to that place so that it can return easily, but upon death, the soul returns via that and annihilates the link as if returns.
Also, as an added thingy, you could say the entity supplying the link, or residue of the links themselves, (whichever) is the source of all arcane power.