Cater’s laidback nature combined with his relationship with Riddle might be why it seems he is unpopular with some members of Heartslabyul.



In his dorm vignette we see him in charge of setup for a tea party, but he spends the majority of his time taking pictures of and hashtagging things for Magicam.



The other students in his group complain about him to Riddle, eagerly anticipating that he will be punished for slacking off.
Instead Riddle leaves after a gentle warning and the Heartslabyul students react with “Turns out you can do whatever, so long as you’re one of Housewarden Riddle’s cronies”.



By the end of the event the Heartslabyul students have misplaced the instructions for putting away the teaware and they blame Cater, saying “Where’s your sense of leadership, Cater? Answer us, Cater! We’re waiting! You were supposed to be responsible for the traditional teaware used at the unbirthday party, Cater. You really dropped the ball.”
Cater surprises them by taking responsibility and apologizing saying “Guess I’m just not cut out to be a team lead. I’m really sorry.”
He takes out his phone regardless, however, and the Heartslabyul students demand that Riddle punish him with his “Off With Your Head” unique magic.



Ace realizes that Cater’s photos and hashtags have created an online catalogue that can be used in place of the misplaced packing instructions, but the nameless students are unimpressed, saying “Tch. That’s guy’s got all the dumb luck.”



Ace tries to take credit for his role in helping Cater, but Riddle and Trey point out that, not only was that Cater’s original intention from the start, but he then used the “mishap” to enlist help from people like Ace himself and increase his Magicam follower count.
Trey says, “He really is a calculating guy”. While quick on his feet, Cater does not seem to particularly excel at studying.



In Riddle’s dorm vignette we learn that Cater is actually in danger of failing his practical magic class—a requisite credit that could result in him being held back a year.
The spell that Cater struggles with autocleaning via implement magic infusion—seems to include a spell formula structure that is “like programming a machine”, and Cater says he gets tripped up because everything has to be performed in a certain order. When asked how he manages his complex unique magic, he says “I’m good at multitasking when it’s all at the same time”, but he is less adept at spells that require a specific order.



Riddle describes this as Cater being good at thinking on his feet, but lacking initiative. Riddle prepares a 300-page study guide from “at least twenty grimoires” despite how the spell in question is above his own grade level, and becomes enraged when Cater fails to memorize it.
Cater says “that’s just not how my brain works”.



Thanks to advice from Trey, Riddle comes up with a more effective study method: he creates a Magicam account and tutors Cater via posts to magicam and hashtags.
Cater passes the test with “an 85 on the written portion and an A on the applied portion” thanks to Riddle’s help.

