Ellie

Ellie is a quick-witted and sarcastic woman with a bit of a mean streak.  It takes a lot to earn her respect, but once you do she's a resourceful and loyal ally.  She doesn't have many friends, but the lucky few see a caring side that she hides from the rest of the world.  Despite this, she falls in love quite easily, but does her best to hide it.

Before the events of the story, Ellie is studying theology as an undergrad.  Her family has been in the ghost/demon fighting business for three generations, and she's studying religions to help her to continue that legacy.  Despite all of her studies and family history, she has a complicated relationship with faith.  She's very knowledgable when it comes to the supernatural, but doesn't actually have a lot of experience under her belt.  Still, she's quite confident in her own abilities.

Those abilities were put to the test when her best friend Nick started acting strangely, then disappeared without telling anyone where she was going.  Ellie spent months tracking her down, suspecting supernatural foul play.  When she finally found Nick in a small northeastern town, her suspicions were confirmed- Nick was possessed, and whatever was possessing her had the loyalty of a sizable cult.  Ellie successfully exorcized the entity out of her best friend, but now the two of them are stranded...

As Below is a video game concept, so here are things about her that have to do with game mechanics:
-she respects common sense and attitude: making 'sensible' or 'witty' remarks around her will increase her opinion of you by 1
-she dislikes cowardice: making 'fearful' remarks around her will decrease her opinion of you by 1
-observant: if someone or something looks dangerous, she'll warn you (will stop if her opinion of you is low enough)
-protective: she'll occasionally take an attack for Nick
-if her opinion of you is high enough, she'd be willing to take an attack for you as well
-professional: her sanity regens faster than average