Deuce offers to carry shopping bags that the prefect has in Book 1, encourages them to share his food during Vargas camp and mentions hearing about the Firelit Sky event from the prefect rather than from Cater or Trey.
Deuce offers the prefect and Grim a place to stay in Book 3, though it will require them sharing Deuce and Ace’s four-person room, and encourages them to reach out to him if they need anything during winter break in Book 4.
Neither Ace nor Deuce respond immediately when the prefect messages them for help after being trapped in Scarabia, but it is revealed that they actually both “came rushing back,” taking public transportation back to school during break to go to their rescue.
Deuce asks Cater to keep the prefect and Grim up-to-date about the Halloween Party during Terror is Trending.
Much like Book 4, the prefect calls Ace and Deuce when they are in trouble in Book 6. Deuce insists on going to the Grim’s rescue during the Charon attack, despite Ace’s efforts to get him to do as Vil instructed and stay back.
When Grim and the prefect return at the end of Book 6 there is an option where Deuce smacks both of them for running off (in the other option they get smacked by Ace).
Deuce scolds them with, “Do you have ANY IDEA what we’ve been through the past two days?!,” but he also says he is relieved that they are unhurt.
In a New Years voice line Deuce offered to help the prefect at Ramshackle as it “gets a lot of snow in winter.”
He apologizes to the prefect and Grim in Book 5 when he loses his temper at Ace.
Twisted Wonderland Reference Note 