Making their way to the top of Shibuya's walls, Shinya is the first one Basteya attacks. They grin when Shinya looks away seeing a second chance to assail him and happily asks whether he has time to talk before raising their sword with Shinya unarmed after being overpowered.
Saito is their leader and Basteya is loyal to him even addressing him as 'lord'. They do at least contemplate having the leash to him cut only dismissing the notion as the one who suggested it is a lower rank than them. Basteya shares that it was Saito who set his plan in motion concerning Shibuya and they simply play their part.Later he shows the full extent of his loyalty to him by allowing him to siphon his own power and lifeforce to empower the Second Progenitor to battle on equal grounds against the First.
They are both members of the Hyakuya Sect, Basteya does not react to this mans sudden appearance through a portal behind him but makes use of it to withdraw from the battle.
They are familiar with Crowley but does not give a proper answer on why they are here before suggesting that Crowley was on an errand or another for Ferid. They do not think highly of Crowley under the impression that he is only a thirteenth progenitor asking what he can do.
Indifferent to Ferid's surprise attack on them, blocking it easily, Basteya does not take Ferid seriously as he was discarded. When asked if Ferid should cut their leash Basteya notes that he cannot as they are a sixth progenitor while Ferid is seventh progenitor. Though they asked what business it was of Ferid's at first when asked if Saito is here, Basteya eventually shares with him that Saito is indeed the one who set the plan concerning Shibuya in motion.
Basteya declares that they do not have enough interest in humans to form an opinion of them either way when it is proposed that they could be friends with them, even when they have a human ally of their own.