Most races are Neutral so you are able to freely choose which side you fight on, or remain neutral. But if you are a race under either the Gods or the Monsters, you must be that. But keep in mind, just because you are with the Gods doesn't mean you are completely pure and good, and being a Monster doesn't mean you want absolute destruction of the world.
Also, when adding your characters abilities. NO 'GOD-MODING' Please keep this 'realistic' and have your muses abilities within reason of their race.
Gods - Those who believe they are on the ritous path, protecting the world from evil and destruction in whatever way they see as necessary.
Angels - Servents fo the Gods and the purest of beings. Appear human and can hide their wings in various ways (ex. tattoos, charms etc.)
Dragons - Worriers of the Gods. Have several races among them including Golden, Black, Fire, Water, etc. Each race has their own special ability.
Monsters - Beings who oppose the binding ways of the Gods. They live freely, often creating chaos in the world.
Monsters - have a human appearance but can live fore centuries. Purebreads are extremely hard to kill and they are sometimes are immortal.
Demons - Don't always appear human, can sometimes shift between forms depending on if it is an ability.
Neutral - Any race that is not naturally on a side.
Examples would be Humans, Sorcerers, Vampires, Shinigami, Mermaid, Weres (not just werewolves: were-tiger, were-bear, etc.), Kitsune, fallen angels, rogue dragons etc.
Mixing races is also an option, just don't go overboard.