Not strong of body, and questionable of mind, she has a kind heart and one special talent. She is not a healer of wounds, or even of people, she heals the souls of creatures. She feels sympathy for even the most hideous and terrible of creatures, and when her tears for them fall upon them, their hearts are moved and their evil ways ended(for a little while at least).
When night falls, we find peace in the knowledge that daytime will return soon, and vice versa. But what if the world was split: daytime and night are two different, coexistent worlds, each with it's own laws and rules. At dawn and sunset, our soul switches to inhabit our other being, our 'twin'.