Impossible Island - RP

We are all ship-wrecked on a mysterious island nobody has ever documented on any of our maps. What lies deep within the island's thick jungles?

Who knows?

-

Rules:
>Be as realistic as you can be.
>Supernats allowed, but please don't be overpowered.
>Make drama.
>Other basic rules.
-

Note for roleplay host (do not copy paste):
The "impossible" part of the island is that there is actually an evil being living there. She/he must be one of your characters. For the element of surprise, make sure they appear during the night when other characters set up camp.
This supernatural being can be a wizard or witch, and she/he makes them participate in different challenges (similar to the gameshow)

The challenges can be your choice. If you need ideas see The Gameshow)

You decide what happens next. What will they do?