And Pie. Everyone deserves Pie.
Darkness, an abyss of shadows where demons reign and nightmares serve; Demons, damned creatures with features, that vary from unnervingly beautiful to grotesque, that send nightmares out to do their biding on mortals; Nightmares, fear that takes the form of dreams, entering our minds to create horrid realities that drive us insane.
Since demons lust for things they can’t have, they will come to earth to make a contract with humans; a binding of sorts. This particular binding is left with a mark, the mark of whatever demon you had made a contract with; the more noticeable the mark, the stronger the binding. And once, you die, the demon will take your soul and devour it, gaining both your essence and your power.