Lucifer

Hanzō Urushihara  also known as  Lucifer is a fallen angel and one of the Demon King's generals. After his defeat at the hands of the Hero Emilia, he was secretly rescued by Olba Meyer, who promised to return Lucifer to heaven if they became allies in defeating the Demon Lord. After being defeated by the Demon Lord, he moved in with Sadou and Ashiya.

Lucifer was born after the destruction of the angels' home-world, making him a part of the second generation of his kind. Once an honored and revered archangel, he was tasked with the responsibility of leading the archangels. Lucifer eventually abandoned his job, feeling it was too boring in Heaven for him to remain. Losing his former status and gaining black wings signifying his corruption, his powers became demonic, reclassifying him a fallen angel. Lucifer traveled to the Demon Realm where he would remain for several years. During his time among the warring demonic tribes, the fallen angel gained a certain amount of power and influence over his new compatriots, though was still not considered a "pure" demon due to his celestial origins. He would later join the young Satan Jacob in the latter's plot to unite the Demon Realm under his flag, the rising monarch proclaiming that Lucifer should feel free to kill him if he ever felt displeased with his leadership.

During the Demon Army's attempt to conquer Ente Isla, Lucifer served as one of the Four Demon Generals. Knowing that he was once an angel and possessed knowledge of Heaven's ways, Satan tasked Lucifer with conquering the Western Continent of Ente Isla, believing his experience would help in dealing with the Church. Upon reaching the countryside of the west, Lucifer set fire to the fields and burned entire villages to the ground, revealing in the chaos and destruction wrought by the rampaging demons as they attempted to purge the land of humankind. In spite of his initial success, the fallen angel met his match when the humans struck back under the leadership of the Emilia Justina, the Church Knight who wielded a Sacred Sword forged from Holy Metal. Though his speed proved superior to her own, Lucifer was cast down by the Hero and thought to be dead for some time, news of his reported demise reaching the ears of Satan, himself. In spite of this, the Demon King refused to believe that Lucifer could have been killed by a mere human, an assumption that would be proven correct. After his master's defeat at the hands of the Hero, Lucifer eventually encountered the rogue Archbishop Olba Meyer, a former comrade of Emilia Justina. The devious clergyman then offered Lucifer a chance to return to Heaven in exchange for help in locating and eliminating the missing Demon King and Hero. Believing he had few other options due to the Demon Army's defeat, the fallen angel agreed to his proposal.