The Lord Of Darkness is the main antagonist of Legend.
He is portrayed by Tim Curry.
He orders his most evil goblin Blix, to kill the two unicorns, the source of light in the mortal world so that it will enter a neverending age of night and become his kingdom once more. His incompetent minions however, only succeed in killing one unicorn by severing its horn. With the other unicorn still in the world, dawn is still able to rise so Darkness resolves to capture the other unicorn however his plans are complicated when he falls in love with Princess Lili, a pure woman whose beauty has captivated him while she is trapped within his domain. He speaks to his father (who is presumably Satan) and asks what to do with her. His father's disembodied voice emanates from a huge fireplace, instructing Darkness to turn Lily to his side through any means necessary.
As he lures her in his chamber, Darkness charms Lili with an enchanted black dress, and as she dances, the dress merges with her. At the same time, the Lord Of Darkness comes through a mirror to meet her, in his true form. During this, Lili's beloved, Jack, Jack's friend Gump and their companions enter the Great Tree, undetected and overhear the brief "talk" between Lili and Darkness as he reveals his plan to plunge the world into eternal night and that Sunshine is what can destroy him.
She tells him that she will be his, if she gets to kill the last unicorn herself.
During the ensuing "Dark Ceremony" that will signal an apocalyptic ice age with the sacrificed blood of the unicorn, Darkness prepares to sacrifice the last unicorn before the gates of the dark void that surrounds the world however Lili breaks the chain holding the unicorn and it manages to escape. Angrily Darkness knocks her unconscious and Jack reveals himself and attacks Darkness before he attempts to kill her. The two warriors engage in a final battle as they sword duel each other.
Finding himself outmatched, Jack grabs the horn of a murdered unicorn and stabs Darkness through the stomach with it. As the sun rises, Jack's companions use the mirrors to reflect the sunshine, chanelling its rays into the Lord of Darkness's lair. Darkness was able to survive the daylight shining on him by holding onto the unicorn horn, during which he taunted Jack that he could never defeat him, but when Jack knocked the unicorn horn from his hand, the light sent him hurtling into space where he exploded into stars.
In the U.S. version of the movie his laughter is heard before the ending credits, implying that he may yet return. This does not occur in the original or Director's Cut of the movie, in which he is most likely dead.