God created the Archangels; Michael, Lucifer, Raphael, Gabriel, and Metatron. Lucifer formed an especially strong bond with his brother Michael. After the creation of mankind, Lucifer began to argue with his brothers and with God over these new, imperfect beings. The arguments became so heated and bitter that Gabriel chose to leave Heaven rather than watch the fighting continue. According to Lucifer, God commanded his Angels to venerate Man, but Lucifer refused, and was cast out of Heaven. As an act of defiance, Lucifer twisted a human being's soul to create the first demon, Lilith. He was then confined against his will in a Cage by God. The Cage could only open if sixty-six of the six hundred seals on the Cage broke. During his confinement, demons multiplied, and some worshiped him as their creator.
In 1972, Azazel possesses a priest at St. Mary's Convent, and killed eight nuns in the chapel. This sacrifice enables him to speak to the imprisoned Lucifer, whose cage opens beneath the convent. Lucifer tells Azazel that Lilith is needed to break seals that hold him captive in the Cage, and that Azazel needs to find a very special child.
Lucifer is freed when the last seal is broken inadvertently by Sam when he kills Lilith. While on Earth, Lucifer, with the help of the Four Horsemen of the Apocalypse, causes chaos and natural disasters. He intends to destroy humanity and to kill Michael. Essential to Lucifer's plan is the possession of his destined vessel - Sam Winchester. Sam and Dean try to find a way of defeating Lucifer without giving in to the plans of Heaven. They attempt to kill Lucifer with the Colt, but fail. Eventually Sam comes up with a plan in which he will allow Lucifer to posses him, and then force him into the Cage. The initial attempt fails, but when Lucifer confronts Michael at Stull Cemetery, Sam manages to gain enough control to force himself and Lucifer into the Cage, pulling Michael in as well.
After Lucifer's defeat, a group of traditionalist angels, led by Raphael, hope to release both Lucifer and Michael to complete the Apocalypse as prophesied. When Sam is released from the Cage, his soul remains behind, perhaps being abused by Lucifer and Michael. After the Civil War in Heaven Lucifer appears to Sam several times in visions, hallucinations, and flashbacks of hell.
Lucifer was once the most beautiful angel in all of existence. God loved him best of all his brothers, even more than Michael. Lucifer was proud. When humanity was created, he was unwilling to accept its place in God's favor (Gabriel described it as the favorite son resenting the new baby). And when God commanded all of Heaven to love his new children more than himself, Lucifer refused. Lucifer pleaded: "Father, I can't. These humans are flawed. Murderous!" After persistent disobedience, Lucifer was cast out of Heaven.
This enraged Lucifer, and he struck back by taking a human woman, Lilith, and stripping her of her humanity, creating the first demon. This unforgivable affront led to his imprisonment in the Cage after a losing confrontation against his brother Michael. He remained there in isolation for millenia. His goal was to be free from his Cage, and to eradicate humanity, allowing him to restore Earth to its original untainted glory. It is suggested that he would also destroy demons, his own creations, because he considers them less worthy even than humans.
Lucifer claims that he never lies, because he does not have to. He promises both his vessels, Nick and Sam, that he will be honest with them. He also says that he sympathizes with his vessels, both of whom are victims like himself. He goes to some lengths to get Sam's acceptance, sparing Dean's life once, and allowing Sam revenge against some of the demons that controlled his life.
Lucifer shows concern for his fellow angels, though it is the archangels he loves most. He captures Castiel, and admires the lesser angel's loyalty in refusing to reveal the presence of his friends. He invites Castiel to join him, and when Castiel refuses, Lucifer respects his decision. Lucifer is remorseful when forced to kill Gabriel, and disappointed when Michael berates him. When preparing to fight his older sibling in their pre-destined battle, Lucifer pleads with Michael to "walk off the chessboard", but Michael determined to fulfill his destiny and serve God. Even so, when Castiel molotovs Michael, Lucifer is outraged by the attack on his brother and obliterates Castiel.
Gabriel criticizes Lucifer, describing his actions as "one big temper tantrum". Death makes a similar observation, dismissing Lucifer s a child who has happened to bind him. Nonetheless, Lucifer sees himself as a tragic figure who was punished for being right, dismissing humanity as a flawed, barbaric race even as Gabriel argues that he prefers humanity because they at least try to do better. He refuses to accept any blame for his actions, which as Michael observes is nothing new, and suggests that God intentionally made Lucifer a devil.
Powers and Abilities
Teleport himself and others.
Overpower primordial beings like pagan gods and all lower-classed angels.
He had the power to make Castiel explode with a snap of his fingers.
Manipulate weather. His presence on earth is signaled by massive tsunamis and tornadoes.
Perceive the true forms of the Four Horsemen of the Apocalypse, as he demonstrated when he saw Death's true form.
Freeze objects. He freezes a window by breathing on it.
Remain unaffected by time.
Bind entities to his command by conducting a ritual, as he demonstrated with Death.
Claims that he would be able to bring Sam back to life if Sam killed himself to stop himself becoming Lucifer's Vessel.
Lucifer has few physical weaknesses. The Colt can damage, but not kill, him. An Archangel Blade can kill Lucifer. Michael can kill Lucifer. If he has the weaknesses of other angels, he can also be confined by a circle of holy oil, and kept out by Enochian sigils.