Lucifer began as God's most favored angel, celebrated as the "Morning Star" or "Bearer of Light" for his supreme beauty and power. His belief in his own perfection ignited outrage when God designated humanity the favored creation. Defiantly refusing to serve humans, he marshaled a rebel angel army and waged war against Heaven. Archangel Michael defeated him, resulting in Lucifer's banishment to Hell alongside his followers. Stripped of angelic status, he became the ruler of Hell and demons.

Confined within the frozen Lake Cocytus in the Ninth Circle (Treachery), Lucifer's initial form manifests as a colossal three-faced demonic entity. Bat-like wings beneath each chin generate freezing winds that maintain the ice prison. Chains of Judecca anchor his arms across all nine circles. This monstrous form conceals his true self: a muscular, humanoid figure with gray skin, goat legs, prominent horns, shoulder spikes, glowing scar-like tear streaks, and tattered wing stumps. A brass serpent-shaped armlet adorns his right arm. He projects a shadowy, tangible form throughout Hell and onto Earth, capable of teleportation, size alteration, and disguise—appearing as Dante, pagan victims, or even God.

His powers include near-omniscience from pre-Creation existence, teleportation, shapeshifting, and complete immortality unaffected by time or disease. He possesses immense physical strength, speed, and durability, along with mastery of dark magic for energy projection, force fields, portal creation, and weapon destruction. Holy magic can hinder but not kill him, as only God or Michael hold that power.

Lucifer's core motive remains escaping Hell to overthrow God and reclaim Paradise. He manipulates through Faustian bargains, exemplified by his wager with Beatrice: Dante's faithfulness during the Crusades would ensure his safe return; infidelity would forfeit her soul to Lucifer. Dante's betrayal ensured Lucifer's victory. After Beatrice's murder, he seized her soul, using her as bait to lure Dante into Hell. Throughout Dante's journey, Lucifer relentlessly torments him with flashbacks of his sins to erode his resolve.

His manipulation extends to others. He promised Dante's father, Alighiero, wealth and respite from torture in exchange for killing Dante. He corrupted Beatrice in Hell, torturing her with false hope and claiming previous brides like Cleopatra and Helen of Troy, planning to father children with her. Lucifer views humanity with contempt, asserting to Beatrice that he merely introduced sin while humans propagated it "like a disease," rendering Earth "another form of Hell" with men as its demons.

Lucifer required a soul "black enough" to break the Chains of Judecca. Historical figures like Alexander the Great and Attila the Hun failed, but Dante's sins—massacre, betrayal, adultery—made him ideal. When Dante shattered the chains, Lucifer emerged from his outer form, revealing Beatrice was merely bait. During their battle, he boasted of imminent freedom and mocked Dante's futility. However, Dante repented and summoned souls absolved during his journey. Their collective power imprisoned Lucifer back into his icy form. As Dante departed for Purgatory, Lucifer's laugh echoed—a serpent formed from Dante's discarded chest tapestry, implying enduring influence and awaiting another chance for vengeance.

Personality-wise, Lucifer exhibits profound arrogance, pride, and misanthropy, dismissing humans as "feeble creations." He is calculating and manipulative, exploiting vulnerabilities through psychological torment and false promises. When defeated, he displays cowardice, attempting to bargain with Dante by offering shared rule of the afterlife or reunion with Beatrice. His dialogue reveals deep-seated resentment toward God for favoring humanity, exemplified by cries of "Why them and not ME?!" during combat.