Dennis Macfield/Relationship

Yūya Sakaki
Dennis stated that he greatly admired Yūya's father and also admired Yūya as fellow Entertainment Duelist. His admiration towards Yūya is what prompted him to save Yūya from Ken and Makoto. Yūya also quickly got impressed by Dennis' Duel that reminded him of his father. Their mutual interest in Entertainment Dueling made them quickly becoming friends and both promised to once again Dueling together again. Thus, Yūya felt betrayed once knowing Dennis' true identity. Despite this, Dennis admiration for Yūshō and and Yūya were genuine, with Dennis himself admitting that the times he spent with him and the Lancers were fun and he seemed to feel certain amount of guilt when betraying Lancers. His regret made him refused to join Yūshō, feeling he doesn't have any right to return after betraying Yūya and Shun. Turning himself into cards was most likely his own way to repent for what his betrayal. Dennis is one of people who appeared in Yūya's mind when he was trying to hold off Zarc's influence, which strongly indicates that Yūya still regards Dennis as his friend despite his betrayal.

Shun Kurosaki
Dennis quickly has an antagonistic relationship with Shun even before he revealed his real identity, which was started from when both of them mocked their respective Xyz Monsters. Shun immediately got suspicious of Dennis' identity and since then determined to expose him, much to Dennis' annoyance. Once confirming Dennis' identity as an Academia Duelist and furthered by the revelation that Dennis was partly responsible for his sister's kidnapping, Shun developed intense hatred for Dennis, brutally defeating him in their rematch, trying to turn him into a card, and even lashed out his anger by attempting to punch him. Unlike Sora, despite his devotion to the Academia and badly injured by Shun, Dennis doesn't show any grudge towards Shun. When Yūshō invited him to join them, Dennis revealed he felt he couldn't rejoin the lancers due to having betrayed both Yūya and Shun, implying a certain amount of guilt and regret for his actions to the the former.

Yūshō Sakaki
Yūshō was Dennis former teacher. During his espionage mission in Heartland, he watched one of Yūshō's Entertainment Dueling and became enamoured by it, leading to his decision to become Entertainment Duelist under Yūshō's tutelage. Dennis respect Yūshō as his teacher, which later also extent to his son, Yūya. However, his loyalty for Academia led the two to become enemies. When the two met again, Dennis acts cocky and boastful towards Yūshō, believing that he has surpassed Yūshō as Entertainment Duelist and has no hesitation to fight him. This seemed that Dennis no longer respect Yūshō like he used to be, though he still referred to him as "Teacher". Yūshō still regards Dennis as one of his precious students, ready to forgive his actions and even tried to convince him to change Academia with Entertainment Dueling together with him. Yūshō wa visibly sad when Dennis instead chose to turn himself into card, and he keeps his card since then.