Toujou Household
Basara Toujou[]
Shiba has shown to make it a habit to jest when it comes to Basara, while the latter is somewhat fearful of him, as a result of his monstrous strength and overall personality. However, unlike Takashi and Kurumi at some point, he held no animosity towards Basara due to his actions of losing control over his Banishing Shift and was just following the orders from The Elders. Even with all of the antagonistic actions that Shiba has done to gain revenge against the Vatican for creating him and the Hero Clan for imprisoning him for several years, he held no anger towards either Basara and his girls trying to get rid of them purely as obstacles to the realization of his revenge. After losing to Basara in their final battle, with his life on the line, Shiba agrees to Basara's terms and ties a master-servant contract with him. A month and a half after tying the contract, Shiba begins to act as a senior advisor for Basara. In his capacity as an advisor, Shiba often provides his opinions to Basara on a range of issues. Although he primarily focuses on the politics of the alliance Basara is trying to build, he often provides a reality check to Basara on the dangers of being too greedy in trying to achieve his goals and in adding more and more people he needs to protect.
Jin Toujou[]
Though not much of their interaction has been shown, Shiba is shown to have great respect toward Jin where he is flattered to have been cloned from a hero who wasn't just powerful, but brilliant after realizing the reason why neither Shuuya or Kaoru Nonaka, his closest friends revealed who Shiba was.
Chisato Hasegawa[]
Shiba's initial opinion of Chisato is partially based upon his memories of Reginleif, who considered Chisato to be a comrade. The first time Shiba actually meets Chisato is during his first battle with Basara, she saves Basara from Shiba's death blow, and he proceeds to mock Chisato's love for Basara by invoking Raphaeline's love for Jin. Although it never happened, he was thoroughly amused at the possibility of getting to fight against her. The next time they meet, the circumstances are much different since Chisato is the only other person outside of Basara who knows he's alive. After becoming Basara's servant, Shiba becomes grateful towards Chisato and displays just a bit of humility since she's the one who saved his life. He uses her as a resource to learn more about Basara and his harem.
The Vatican
Albareos[]
Most of if not all of Shiba's anger is directed towards Albareos and the Vatican for creating him as he continues to plot every plan in an attempt to gain his revenge against them, to where he chooses to even use the Four Gods to summon and assimilate Kouryuu into himself. He is later seen to openly mock the Holy King's attempt to kill him, which later failed.
Hero Clan (Japan)
The Elders[]
Like the Vatican, Shiba's anger is directed towards the Elders for having him imprisoned for several years, but he has shown to follow their orders in order to maintain his position as a hero under them to prepare for his revenge in using the Four Gods. Shiba knows how the Elders act and uses whatever situation they enact to his advantage as proven when they summoned Basara and the others who they felt were something a potential threat.
Demon Realm
Balflear[]
Shiba and Balflear have met one another during their times in the Vatican, and they shared their same sense of anger and vengeance, which caused them to develop a trust in each other. It was most proven as Balflear infiltrated the Vatican under the alias of Celis' aid named Cleo Angeles.
Reginleif[]
Shiba's relationship with Reginleif is mostly unknown, but can be speculated that he hated him due to his participation in his creation. However, that ended in his benefit as Shiba later absorbs him into himself, killing him in the process, gaining his power and soul to strengthen himself.