The simple answer is Mature Young Adult Contemporary Fantasy.
Here is one of the rejected query letters I have sent to agents regarding my current project. Tell me, would you read it?
The son of a human and a succubus. An immortal. The product of a demon's plan gone awry. He is a subspecies of vampire called The Enedev. He is driven to heal the ill and save the dying, defying instinct and denying primal hunger while looking for the one who will complete him. When he finds her he realizes she is not like him, her people not like his, and yet he is drawn to her. Drawn to her even though she is evil. The problem is that there are two of her. She has an identical twin who is human. A human who can do things no other human has ever been able to do. She can see things no human has ever been able to see. Caught in a tri-species web of love, hate and jealousy all governed by an outsider's subliminal persuasion, The Enedev must choose between the twins. He must protect his family's anonymity and above all save the people who seem to be dying in irrational patterns at his every turn.
In reality, the book is written in first person by the main protagonist who is the HUMAN TWIN but I didn't want to write the REAL QUERY here because it contains too much info that is too easy to steal. (If I sound paranoid, well, I am) The Antogonist is the EVIL TWIN. The story in its entirety contains one large plot containing 2 different protagonist/antogonists and several mini-plots within. As you can imagine there are several characters due to the plot layout including mostly made-up but some truly mythological creatures.
The book is called Shield of Persuasion. It is the first in a trilogy and CANNOT stand alone. The other two books are a necessity to finish the story. If I don't receive a decent agent offer soon I may be looking into self publication. We'll see how that goes.
The Fat Chick