After Epel runs away during rehearsal in Book 5 Deuce confronts Vil for dismissing Epel’s efforts. Vil responds, “You have no bandwidth to spend worrying about others. You’re far behind the other members in all aspects of your performance…don’t talk like a full-fledged ensemble member when you’re still dead weight.”
Deuce apologizes, and Grim asks why Deuce keeps getting involved in arguments between Vil and Epel and Deuce explains, “I’ve seen something in Epel ever since we ran into him by the courtyard well. I think…he and I are a lot alike…It’s about wanting to change, but not being able to…”
Ace also comments that the two are similar during Halloween and his birthday (“I think on the inside, Epel’s basically like Deuce”).
Deuce borrows a blastcycle to take Epel to a beach for a cathartic scream, and he yells at the ocean about how he is never going to give up, saying it is something he does whenever things aren’t going his way: “I drive to the beach and let it all out at the top of my lungs. It always makes me feel better.”
Deuce says he invited Epel out because he thought that maybe Epel was like him, at which point he realizes that, while he’d had Epel “pegged as a quiet, timid guy”, he was very wrong.
Deuce follows up with “I bet nobody in this school has you beat in the cuteness department!”, maybe still not fulling understanding Epel’s position.
This comes up again during Glorious Masquerade when Epel is envious of the “knightly” looks of the other characters, saying that his outfit is the only one that’s cute. Deuce responds, “Oh yeah, it totally is cute!”
After some encouragement from the others, including Deuce, Epel feels better about his look.
In Book 5 a group of unnamed and unseen strangers grab at Epel on the beach, mistaking him for a girl, and Deuce goes to his defense. Deuce insists on taking responsibility for removing Epel from the safety of the school by handling the situation on his own.
We also see Deuce protecting Epel during the New Year’s event and Phantom Bride.
When trying to defend himself against the bullies on the beach Deuce accidentally wipes them out in a single hit, not knowing how it is that he did it.
When Deuce and Epel return to Pomefiore they apologize for leaving campus without permission and getting into a fight, with both characters trying to take full responsibility in order to spare the other from Vil’s ire.
Their punishment is to run thirty laps around Pomefiore dorm.
Twisted Wonderland Reference Note 