Crimson moon, the unexpected god

In a small village nestled in a valley at the base of a huge mountain, people have grown up for centuries knowing a story about a terrible beast that lives in the mountain and every time there is a crimson moon a Dreamer arrives to make sure the beast remains asleep. For if it awakened it would destroy their beautiful home. Except this time it is someone else who emerged from the shadows of the trees, dressed in a light green half coat.