Demi-Human Alliance[]
Valga Cromwell[]
Valga found Sphinx through some means and inducted her into the Demi-Human Alliance. She conspired with Valga during the Demi-Human War and listened to his advice on how to use her Magic Circles. In return, she revived the corpses of the fallen demi-humans and humans to gain more soldiers for the Alliance. However, Sphinx also threatened to kill him on at least one occasion and chose to disregard how he wanted to keep Libre alive in order to further her own goals.
Sphinx thought highly of Valga’s tactical mind, even utilizing one of his stratagems during the Great Disaster and becoming shocked when it failed.
Libre Fermi[]
Sphinx saw Libre as a tool whose life was an expendable utility. She did not mind asking Valga whether or not he needed to die, nor did she have any inhibitions upon killing Libre in order to make him into a corpse soldier and cover her own escape, though she did bring him back to Valga so they could continue using him as a resource in their plans.
Priscilla Camp[]
Priscilla Barielle[]
Sphinx held a unique interest in Priscilla, as she was the reason that the Witch was able to establish her own emotions and understand others' feelings for the first time, as well as the cause behind her having the qualifications to become a zombie. Sphinx admires Priscilla's judgement, is perfectly willing to converse with her. However, it was revealed that she harbored a sense of anger and a need for vengeance ever since she halted her plans in the Barielle Domain, and thus, she had actively kept her alive, rather than reanimating her as a corpse soldier, so that she might bear witness to Sphinx’s success. When this ultimately backfired on her and Priscilla escaped the prison made specially for her, Sphinx’s rage reached its peak, and every zombie of her remaining moved to attack and kill her. In the end, Priscilla struck her down, congratulating her as she passed away.
Al[]
Sphinx was already aware of Al’s existence due to his connection to Priscilla. After screaming the name of Sphinx’s creator, however, when they confronted each other in the Great Disaster, Sphinx became much more interested in Al, and she would engage in combat with him while wishing to draw out answers. After her defeat at his hands, she seemed to take pity on him while comparing him to herself: a person with an incomplete purpose.
Emilia Camp[]
Natsuki Subaru[]
Due to Subaru foreseeing Sphinx’s attack and stopping Valga's “stratagem,” she regarded Subaru as a foreign entity that could disrupt her plans. During the Conquest of the Corpse Capital, her instincts would tell her that Subaru was involved, so she would confront him, where he would claim to be her natural enemy. She would also be confused by Subaru, with him speaking the answers she wants before she could finish her question, or when she pulled a poison from his behind his molar despite the situation not being suitable for having one. Having been outsmarted by Subaru, she would nearly meet her end by his and Vincent's combined efforts. When they met again later, Subaru would confront her one last time, telling her happy birthday before having her be devoured by Spica.
Beatrice[]
Beatrice first became aware of the Witch’s existence during Arc 8 when she encountered her as an undead. After meeting each other in combat, Sphinx would deem her one of the main threats of the Great Disaster and have her marked. They would meet again in Lupugana, where they would fight each other again, and Sphinx would lose again.
Roswaal L. Mathers[]
Sphinx did not seem to be aware that Roswaal L. Mathers and Roswaal J. Mathers bear the same soul. That said, Roswaal’s hatred for her remains from those days, and the two would meet in combat. Because of his mastery in magic, she would deem him one of the more dangerous threats and have him marked.
Emilia[]
Although Emilia first saw Sphinx on the coupled dragon carriage, the two did not interact with each other. However, when they encountered each other in the Imperial Capital, Sphinx showed clear surprise by Emilia’s resemblance to the Witch of Envy, calling her by that name, while Emilia was shocked to see her resemblance from Ryuzu to change to that of Echidna. The two corrected their misconceptions, but Sphinx was still intrigued by the connections that they shared. Similarly, Sphinx seemed to have already been aware of the existence of Emilia as a Royal Candidate. That said, the two still met in combat when Emilia mentioned she was looking for Priscilla.
Lugunicans[]
Roswaal J. Mathers[]
Sphinx initially viewed Roswaal like the other humans she was accompanying; however, the Witch quickly discovered that she was different and thought that Roswaal could help her in becoming "complete". At the Battle of Aihiya Swamp, her impressions were quickly shattered when Roswaal asserted herself as a formidable threat to Sphinx. She later sought to exterminate Roswaal during the Battle of Lugunica Castle, but she ultimately failed and was forced to make an untimely escape.
Leip Barielle[]
Leip was the one who captured Sphinx and saved her from being killed by Roswaal. He thought of Sphinx as a tool for his ambition to gain control over the Kingdom and disposed of her limbs to pressure her into obeying him. Despite receiving this treatment from him, Sphinx appeared to express some degree of concern over his choices and offered suggestions to improve his plans. However, Leip ultimately denied any amendments, and she chose to follow his orders until he was permanently incapacitated and died.
Imperial Family[]
Vincent Vollachia[]
Like with Priscilla, Sphinx harbored a certain interest in Vincent, wishing to take him alive rather than killing him and turning him into a zombie. Naturally, Vincent saw her as a dangerous enemy as the individual behind the Great Disaster. When Vincent’s group and Sphinx clashed, she would attempt to negotiate with him to bring him alive, and when he refused, she threatened the lives of those nearby to try and coerce him. However, this was part of Subaru and Vincent's plan, and the latter used his Yang Sword on Sphinx, burning away her very soul until she pooled her knowledge together to complete it, making the emperor indirectly responsible for casting away the Witch's shell, thus saving her life.
Nine Divine Generals[]
Cecilus Segmunt[]
As Cecilus was responsible for her initial death towards the beginning of the Great Disaster, Sphinx noted him as a considerable threat. When she went to confront him and Al later to kill Arakiya, she even set a dead man’s switch on her body in preparation for Cecilus. Similarly, she was surprised that Cecilus was able to recognize that she was the same person despite carrying a different appearance. In their rematch, she would use various combinations of magic to confront him, even utilizing Al Shario. However, her amazement with the man’s strength grew further when Cecilus successfully cut through the star. Later, the two fought once more during her final stand.
Arakiya[]
As part of her revenge scheme against Priscilla, she nudged Arakiya to devour the Stone to prevent the spirit’s further abuse. Her real goal: to cause Arakiya to implode from the sheer mass of mana that was the Stone. However, things turned sideways when Arakiya managed to maintain her form and when Cecilus managed to quell the Stone’s power within her. With her plan now in shambles, Sphinx personally sought to end Arakiya’s life, considering her death synonymous with Vollachia’s.
Kararagians[]
Halibel[]
Sphinx considered his presence to be a massive threat to the Great Disaster. She later fought Halibel during her final stand.
Others[]
Spica[]
Coming across her in Lupugana, Sphinx would immediately recognize her use of the Authority of Gluttony, and she would attempt to kill her after pointing it out, regarding her as a threat. Eventually, Spica devoured her name, resulting in her final demise.