Riddle’s face will often turn red when he is enraged. Riddle is frequently making an “ugiii” sound that has been localized as “yeargh” on EN, a reference to the Queen of Hearts: it is similar to a sound made by the Queen of Hearts during the trial scene of the Japanese dub of the original Alice in Wonderland animated movie.
It seems rare to see Riddle manage to calm himself down once he is in a rage, but we see it happen at least once when he tries to talk himself out of being goaded by Floyd in a vignette.
Cater says, “Riddle’s crazy strict when it comes to the Queen of Hearts’s rules, but it’s not like he gets mad over just any little thing.”
In Book 2 Riddle confirms this, saying, “I will be perfectly pleasant if you obey the rules!”
When Ortho describes Riddle as “an offense-heavy ranged DPS” Trey says, “He wasn’t like that at all when we first met. When I saw him send Floyd flying during their orientation, I almost questioned if it wasn’t someone else who happened to share his name. But looking back on it now, he was the spitting image of his mom, the way he raged and yelled while the teachers held him back,” so it Riddle’s infamous raging is possibly his mother’s influence.
Seeing Riddle “overcome with anger” Rook observes, “impulsiveness is part of the Roi des Roses’ charm.”
After the events of Playfulland Ace asks Vil for advice on “calming Riddle’s rage,” and Vil responds, “Own up and apologize! Any attempts at one of your trademark clever excuses will only serve to anger Riddle further. The best way to earn Riddle’s forgiveness is to accept his anger head-on.”
This seems to be something Ace is particularly reluctant to do, with Deuce offering the same advice in Book 1 an Ace responding, “I hate this so! SO! Much!”
Vil and Deuce seem to be correct: Cater apologizes to Riddle in Book 1 and suffers no consequences, while Riddle tells Ace that he had been considering removing his collar, but as he has not “detected so much as a hint of remorse,” he opts to leave it in place.
Cater repeatedly encourages Ace to apologize during the Unbirthday Party of Book 1, and both he and Trey apologize when it is revealed that the tart Ace presented Riddle with a rule-breaking tart because of their encouragement.
Neither Cater nor Trey is collared, while Ace, Deuce and Grim are. Trey follows up with, “We’ll try to calm Riddle down, so maybe he’ll let you back in the dorm after you apologize,” and Ace responds, “I will NEVER apologize!”
After collaring an unnamed Heartslabyul student for a rule infraction, the student is instructed to earn his freedom through weeding the garden and writing a 5,000 word apology.
Ace chooses to duel Riddle in Book 1 to get his own collar removed rather than apologize.
When Riddle is reticent to following Idia’s instructions in Book 7 Idia does not take it well, mocking him for being unable to memorize multiple coding manuals in under three minutes and then yelling at him to “Go whine in the corner for all I care!”
This surprises Riddle, who responds, “Seeing someone even more agitated than me actually calmed me down.”
Twisted Wonderland Reference Note 