He debuted in " Supernatural Thrillers" #5 (August, 1973). In the 11th century BC, Nephrus was the high-priest of Pharaoh Aram-Set. He witnessed the forces of his employer capture bring the captives of the Swarili tribe. He informed Aram-Set that N'Kantu, the leader of the slaves, was plotting against them. But his precognitive powers informed him that the temple they were all building would be completed. He felt certain that there would be time to deal with the rebellious slaves following the completion.
Nephrus was wrong. As soon as the temple was completed, N'Kantu staged his revolt. The slave killed Aram-Set with a spear. Nephrus was able to use a potion to paralyze the chieftain. Ending the rebellion, Nephrus was left with what to do with N'Kantu. He had the man turned into a Living Mummy and then had him entombed. N'Kantu was destined to survive for millenia. Nephrus was not that lucky. An earthquake caused the temple to collapse upon him ending the life of the sorcerer.
In #14 (August, 1975), Dr. Alexei Skarab was using the Ruby Scarab, a magical artifact, when contacting the spirits of his ancestors. That of Nephrus among them. He was taught in brief the story of the Scarab and how to use it.
In " Marvel Two-In-One" #95 (January, 1983), Gamal Hassan, another distant descendant, was introduced. Gamal Hassan used the Spirit Gem of Nephrus in an effort to gain the powers of long-dead Nephrus. It worked too well. He became a host to the living spirit of Nephrus.Nephrus did not have time to enjoy his new existence. Gamal had abducted Alicia Masters to turn her into his bride. Consequently Nephrus had to face an enraged Thing, a still active N'Kantu and Lillian Templeworth. The latter being a former assistant of Gamal, knew many of his secrets.
Nephrus gained the upper hand in combat with the Thing and N'Kantu. But he was not paying attention to Alicia and Lillian. The two ladies were able to use the Crown of Hathor, another mystical artifact, to separate Nephrus from the Spirit Gem. He was left severely weakened and his true age started catching up to him. His body soon turned to dust.
In " Legion of Monsters: Satana" #1 (August, 2007), N'Kantu summoned the spirit of Nephrus. He was hoping his ancient foe would be able to end his undead state. Either returning him to true life or granting him true death. Nephrus turned up to have no idea of how to perform either task. But the two were soon joined by the owner of Nephrus' stolen spirit: Anubis. He was able to reclaim Nephrus' soul and gained N'Kantu as an agent in the mortal realm.