The Darkness was an almost godly demon from the film Legend.
He has one of the only two existing unicorns killed and captures the other. He also kidnaps Princess Lily and attempts to turn her to evil. He manages to seduce her and almost gets her to kill the last unicorn, but Jack appears, and she remembers who she is and refuses to kill the unicorn. Angrily he attacks but Jack fights back, whilst they're fighting the others relay the light of the setting sun to kill him. Darkness shouts that he can never be destroyed, claiming "I am a part of you all," just before he is killed by the light. As the film ends he is seen laughing away in the distance.