Roen

Roen is the loyal servant and watchdog of Lord Maksis. He's strongly devoted to Maksis and intends on reviving him to his previous power by obtaining the Grimoire.[2]

As a dog, Roen is rather laid-back, often resting on the student council's couch. While rarely interacting with the student council, he and Shiki have extremely hostile interactions, to the point where Roen's repeatedly shown disdain towards Shiki by biting and growling at him without second thoughts.[3] Even when in his human form, Roen often makes a point of avoiding Shiki, most likely intimidated by him.[4] While in this form, he enjoys having Ritsuka pet him.[2]

Despite his amicable appearance, Roen is very manipulative and deceptive, taking on the appearance of a desperate, dismissed dog after Maksis' fall by the hands of the Arlond family head, and went into the family as an apparent servant, even accompanying Rem for the grand majority of his day at school.[2]

Although he acts polite towards Ritsuka, he has no sense of her personal space and has no qualms licking her without warning nor permission. He's intent on claiming the Grimoire within her for Maksis' personal use and doesn't mind endangering her life to achieve his goal.[2]

He takes much in stride and with a smile on his face, always keeping his calm and always avoiding major trouble. However, when pressed, Roen doesn't hesitate to endanger the lives of others, namely Ritsuka, and even threatens to rip her heart out during his close altercation with Rem in the large hallway he took Ritsuka to.[2]

However, after he learns of Maksis' true intentions, Roen loses much of his drive for having misinterpreted Maksis' goals for Maria and Ritsuka.[4] It is only after Ritsuka clears thing up herself between them that Roen regains much of his confidence, having a new goal and motive, and displaying fierce loyalty towards Ritsuka nd her mother, regardless of Ritsuka being on the Devil or Human path.