Lucifer was originally the first archangel on Heaven. He was seen to have the first romantic relationship on Heaven with the third Archangel Lucinda, as he is said to have created "love" on Heaven. When learning that Lucinda no longer loved him and her true love was with the sixth angel, Daniel, he became highly jealous and was part of the cause that cursed by Lucinda and Daniel. He later attempts to reclaim Lucinda and her love, but unfortunately her love for Daniel was to great in the end he allows Lucinda and Daniel to be freed from their curse.
In the Series
In Passion, Lucifer appears as Bill, a guide to Luce who helps her travel through the announcers to different lifetime. Throughout the travelling Lucifer tells Lucinda in a way of freeing herself and Daniel from the misery and heartache, to cut herself with a Starshot but once in Egypt, seeing that Daniel loved her truly and not because of a curse she refused to kill herself. Instead, she asked why he asked her to and Lucifer reveals himself as the "bad guy" where he tells her that he wants to get all the fallen angels into a Announcer and take them to the future where Lucinda will be his again and not Daniel's as their love would not have grower larger as it has over seven thousand years. He later disappears telling Lucinda that he will have his revenge and his love.
It is revealed during Rapture that he and Lucinda were in love with each other. But Lucinda decided that she loved Daniel, and so Lucifer cursed her.