Vlad's first known master who was known among his peers as the Red Glare. Kazuma's infamous nick-name however contrasted with his intentions of wanting to save others. While Vlad himself was never shown interacting with Kazuma, Vlad's thoughts on his previous master was imparted to Ouka who for the longest time, was not aware of her adoptive father's ownership of him. Vlad was entertained and slightly annoyed with Kazuma's dual-nature of being a ruthless and formidable Inquisitor on duty while being unnaturally kindhearted and concerned when it came to dealing with civilians caught in the inevitable crossfire. While Vlad wasn't completely invested in praising him, he came to respect Kazuma's conviction in wanting to fight and protect what he believed was right.
Vlad's second known master who happened to be Kazuma's adopted daughter. Like him, Ouka was renowned for her prodigious skills but known also for her cruelty. Vlad's initial provision with Ouka in their partial contract was for her to avenge her family and while he did not admit this until later, he had planned to consume her if she had continued with this wasteful intention. In the time Ouka avoided making a full contract, Vlad constantly reminded her that she could tap into his unleashed might if she accepted him. Ouka's interaction with the platoon finally brought the change in her heart that shifted her single-track goal of revenge into a contract based around protecting the people she cared for and Vlad gladly accepted her new terms. Before and after Ouka's alteration to their original contract, Vlad never ceased in taunting her and correcting her mistakes.
With the new contract in place, Ouka's acceptance of Vlad as partner had both of them opening up to each other. However, while Ouka's acceptance was rooted in her change of heart, Vlad was always willing to share his honest thoughts but was never able to fully do so due to Sougetsu's control over her. Nonetheless, Ouka wanted to know more about Vlad and his previous contractors and he found Ouka most similar to Kazuma for obvious reasons not apparent to Ouka at the time. Both were incredibly stubborn, had trouble relaying their thoughts, and while they were violent at times, their intentions were noble. As Vlad began seeing more of Ouka's selfless acts and determination, he counseled her and act much like a guidance figure for her. This eventually culminated towards his immense regret in being unable to save Kazuma to spare Ouka from her current life.
The Relic Eater under contract with Takeru Kusanagi. While there is minimal interaction between Vlad and Lapis. the former lectured the latter when she was distraught in how she could continue serving Takeru when there was a chance that she would devour his memories. Vlad proposed the solution that he and his master could assist her in the endeavor in keeping Takeru safe from Lapis' overwhelming power.
The head of the Inquisition who controls every Relic Eater granted to his Inquisitors. Vlad was no exception to this and Sougetsu had complete control over him during the 35th Platoon's escapades preceding their departure from the academy. While not explicitly shown, it can be assumed that Vlad was not completely favorable with Sougetsu as he is most likely aware of Sougetsu's responsibility in Kazuma's death. To add insult to injury, he had her contracted to Ouka and be unable to reveal the secrets of her family to her.