Lucifer Morningstar is a character in the TV series Future Constantine.
Lucifer was one of the first angels God created. As an angel Lucifer would constantly come up with new ways to mess with mortals until one of his plans went to far, that plan was to have Cain kill his brother Able.
After he was told he could never prank mortals ever again Lucifer became hateful towards God and attempted to start a war but it ended in Gabriel casting him away to hell where he would become known as the fallen one.
In the first season of Future Constantine Lucifer is an antagonist who escapes from hell and attempts to kill all angels and mortals, however in the second season he is a main character who wants a war that is going on in hell to stop so he tells Jack he will help him get out of hell as the war is being fought over him.