A second progenitor and the current leader of the Progenitor Council. Urd was the one who sentenced Ferid and Krul Tepes to 10 days of exposure torture. He is intent on believing the pair are traitors.
A third progenitor and former queen of Japan. Although Ferid "loves" Krul — or more specifically, her power — Krul loathes Ferid to an extent to where she wants him dead. What keeps her from killing him is blackmail: Ferid bringing Krul's attention to the possibility that he might have someone in line to reveal his secrets to the Progenitor Council come his death; hence alerting the council of Krul's involvement in the Seraph of the End. Ferid considers Krul to be his "parter in crime", as they share the same secret. Nonetheless, Ferid greatly enjoys teasing Krul, even though he often derives a violent response.
A third progenitor who once silenced Gabel Parthe from goading Ferid about his lower rank. Lest does not seem to have much respect for Ferid, well-aware of his eccentrics and hence ripping out his heart simply to quicken the process of extracting an answer. On a separate occasion, Lest dragged Ferid by his hair.
A fifth progenitor and member of Urd Geales and Lest Karr's army. Ky described himself as "insane" as Ferid for the both of them have lived so long [in boredom]. Nonetheless, Ferid appears to irritate Ky, provoking him to such an extent that Ky declares he will bury Ferid's severed head himself once he returns.
A thirteenth progenitor and member of Ferid's faction. Ferid turned Crowley into a vampire using Saitō's blood instead of his own, making Crowley his "brother" for they share the same sire. Crowley has since spent his vampiric years following Ferid under the claim "getting involved with Ferid's plans always means something interesting will happen".
A seventeenth progenitor and aide to Crowley Eusford. Chess is a member of Ferid's faction, but dislikes him, believing him to be "sneaky" and "tricky" and she "never knows what he's thinking".
A seventeenth progenitor and aide to Crowley Eusford. Horn is a member of Ferid's faction, but agrees with Chess Belle when she states her belief that he is "sneaky" and "tricky" and one "never knows what he's thinking".
A city guard and member of Krul Tepes' faction. Mikaela approached Ferid at one point after being herded into Sanguinem along with the other Hyakuya orphans, having heard that Ferid would "buy anything one wanted" in exchange for blood. Hence, Mikaela allowed for Ferid to drink his blood directly — although his true intentions were to steal a map and pistol from Ferid's mansion to aid his and the other orphans' escape. Ferid predicted Mikaela's movements and awaited him and the other orphans at Sanguinem's exit. Once the orphans arrived, Ferid slaughtered all of them with the exception of Yūichirō Hyakuya, and fatally wounded Mikaela; giving Yūichirō an opportunity to escape. Mikaela's life was saved by Krul's decision to turn him into a vampire, on the basis he is a seraph. Once Mikaela is turned, Ferid expresses his concern regarding Mikaela's appearance: he is at the age in which Ferid finds most "beautiful" — "just barely" — but is continuing to age as Mikaela has yet to feed on human blood. Ferid indoctrinates Mikaela to think of humans as "greedy", and finds thorough enjoyment in teasing him, though most often his response from Mikaela is "shut up" or something violent. Ferid states that Mikaela is his favourite servant.
A city guard and member of Ferid's faction. Lacus works alongside René Simm and Mikaela Hyakuya, behaving respectfully before his superiors and not hesitating to follow Ferid's orders on the battlefield.
A city guard and member of Ferid's faction. René works alongside Lacus Welt and Mikaela Hyakuya, behaving respectfully before his superiors and not hesitating to follow Ferid's orders on the battlefield.
Lieutenant Colonel and leader of the Moon Demon Company. He and Ferid first met in Guren Ichinose: Catastrophe at Sixteen. It is likely that Guren was the one who Ferid was addressing as his "ever-so-amusing partner", as while they may appear to be enemies, Ferid and Guren have been working together for quite some time.
Former Special Private and member of the Moon Demon Company. Ferid slaughtered most of the Hyakuya orphans, fatally wounding Mikaela Hyakuya before Ferid was shot by Yūichirō. Said rescue attempt by Yūichirō turned out to be in vain, as soon other vampires arrived at the scene and Yuichiro was left with no other option than to flee; leaving Mikaela behind. Ferid stands as the leading cause of Yūichirō's hatred towards vampires — being the one who killed his "family".
Former second progenitor and vampire. Saitō is Ferid's sire, having turned Ferid into a vampire long ago. He considers Ferid to be an "odd one", and Ferid refers to Saitō as his father or "papa".
The demon sealed within Guren's sword, Mahiru and Ferid first met in Guren Ichinose: Catastrophe at Sixteen at the same time Ferid met Guren. Ferid has been working with Mahiru and Guren for quite some time.