[quote=@Expendable]
What sort of immortals are we talking about? Highlander immortals? Phoenixes? Ms. Jones? Nanny McPhee?

Are vampires immortals or are they monsters?

Do you get Angels? Demons?

What other supernaturals will we encounter?
[/quote]

Pretty much all of them, but there's no taxonomy to it. Rather than being things like different species, immortals are effectively humans who have rationalized their own immortality. Someone could rationalize it as being a vampire and devour. Someone could rationalize it as a Matrix Agent Smith style body takeover. Someone could view it as though they were a snake, shedding their previous form when it has become too damaged.

As for the supernatural, it functions off of the unconscious and abstract concepts. Hounds. Gargoyles. Ghosts. The moon actually being an eldritch entity. The main factor of the supernatural is that it's life without life. The supernatural can not think or plan nor does it have instinct. They're effectively programs that do what they are thought to do (with a side of being attracted to human life).

So if vampires are immortals or monsters: they can be both. An immortal vampire is a human with vampire tendencies and just can not be killed by any means. A monster vampire is a more beastial, abstracted form that does not have rationale beyond drink blood and hot chip, plus they can more easily die.

Angels and demons are the same. Immortal angels and demons are still human. They just have wings and stuff related to angels/demons. Supernatural angels are more "do not be afraid" and suck the life out of you when they forcefully embrace you. Supernatural demons--there's a lot so I won't get very specific.

Pretty much there is no limit to what you encounter as a supernatural entity. As long as I have a rationale basis--people fear it, it's a concept people know, etc--it can be an enemy. Basically, some classical enemies, some weird enemies, and some absolute curveballs.