I'ma take a shot at writing Dark.
But that torture, that anguish, that solitude didn't leave the great being when he split himself. Oh no, there was one being who's horrible existence was to contain that pain and suffering. It, much like the great being, couldn't contain all this loneliness. It changed all it's sadness into bitterness and hatred. It wouldn't poison you, no, but it would poison your friends so you could watch them die slowly. It would steal, not only what you had, but your strength, your energy, your very life itself. And when the moon was high and the children were scared, it grew strong and it's rage billowed in waves of destruction. With every hit, every time you got weaker, it grew stronger. And even if you tried to see and fight, half the time it disappeared, and you were left wondering, wondering, if it had ever been there at all. This being, the darkness, is myth among the people of the world. Vampires, werewolves, all revolved around this mysterious dark force that created all the horrors. And as the people turned away from darkness, calling it evil and horrible, it's sadness grew ever more.