A group of characters in a modern fantasy world of demons and angels

People can make a sacrifice to summon an angel, or more controversially; a demon, to grant them magical powers. The sacrifice? Passage in your soul. Not all who summon are strong enough to stop a full posession, but twins Cephlir and Ceris thankfully are. And now they're going to try and save the world of Elstus.

Contains religious themes.