After Deuce leaves a VDC rehearsal in frustration in Book 5 in response to Ace mocking his intelligence Rook follows him, giving him a lecture on the power that Deuce has within himself: “Would you expect an unhatched chick to accurately gauge their own limits? Non.”
Soon after Deuce takes a blastcycle and Epel off campus, getting into a fight on a beach. Vil is not amused but Rook asks him to forgive the two first-year students.
Rook and Deuce also overlap during Port Fest where Rook asks Deuce to model for him, though Deuce struggles to understand Rook’s criteria for a good picture. (Rook: “Your body language is the image of ennui! How fresh!”)
At the festival Deuce mentions how “intense” Rook was about photography the other day and Rook assures him that he will not be getting any anyone’s way. (“You look as though you are readying for an attack!”)
When flamingoes escapes from Heartslabyul Deuce is left to hunt them down, and he comes across Rook sharing a shrimp sandwich with them in the school’s courtyard.
Rook suggests that Deuce try and herd the flamingoes with flight magic. Deuce responds that flight magic isn’t a particular strength of his, but he does not want to disgrace his housewarden by letting an uncoming unbirthday party be cancelled. Rook responds, “The arrow of your loyalty to the Roi des Roses has pierced my heart! You work tirelessly and diligently to ensure that your master’s reputation remains unblemished.Such pure devotion! What can that be called, if not beautiful?,” and volunteers to help Deuce with the flamingoes.
Afterward Rook observes, “The Roi des Roses has fine vassals, from what I can see.”
After Deuce injures himself in the process of saving Idia from a falling chandelier during Glorious Masquerade Idia volunteers to stay behind with him (“Why get all worked up trying to escape when you could just kick back, chill, and go out peacefully?”).
Inspired by Idia’s courageousness, Rook announces that he will be staying with Deuce instead, despite Deuce’s protests.
After the group leaves them Deuce admits that he is really happy that Rook stayed back with him.
When Rook later tells him that it impossible to exterminate the flowers Deuce still refuses to give up, and Rook admits that he had already resigned himself to his fate, ultimately deciding to struggle alongside Deuce, instead: “Let us dance the night away in this firelotus garden!” (Deuce: “I don’t know what kinda metaphor you’re goin’ for, but I think I get what you’re saying!”)