I need some genre help

People ask me all the time what my novel's about and what genre is. I can't answer their question because I don't know myself. So, I'm going to give you a short synopsis (or as short as I can make it) and some of the major themes.

Synopsis

Sage and Cory, fraternal twins, go to a high school party one night, and while driving home, they get into a car accident. They are transported to a purgatory-like place. Cory is kidnapped by Hades, the main antagonist. Sage finds herself in the middle of a war that could determine the future of the world. She is entrusted by Zeus, the leader of the protagonist group, to get her and Cory out of there as soon as she can and he gives her 2 "Fate Coins" that would allow her and her brother to get out of there. Unfortunately, before she and her brother can escape, she loses one of the coins. Cory forces her to leave in his place and he helps the imprisoned rebels to escape from Hades' dungeon. Once regrouped, Cory is faced with a moral decision, to betray the rebels or watch his family die. He ends up betraying them and the rebels almost get captured. Zeus, however, does end up being captured and killed, Hermes, the second in command, ends up assuming his role and leads them all into battle. There's a confrontation between him and Hades. Eventually, Cory is sent back to "the real world" and as a sort of gift, Hermes is aloud to return as well.

Plot Themes

1. Life and death are steps on a greater path.
2. Appreciate the gifts given to you.
3. There isn't anything to fear, not even fear itself.

Those are just a few of the themes, I built in a lot more into the plot. Really it's up to the reader what to take from it.
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