Leona and Riddle

In the second novel Riddle tells Leona directly that has always respected him for being so beloved: 

“Riddle confronts the glowering Leona with determination. ‘I am not mocking you. Leona-senpai. I respected you.’ Cater looks at Riddle with surprise, while Ace and Deuce’s eyes go wide. None of them could have ever imagined Riddle saying such a thing, and with such honesty.
Yuuya remembers what Riddle said when they were discussing Malleus: a good housewarden. A respected housewarden. Riddle has always longed to know more.
‘I envied you, for how the students admire you. I wanted to be a housewarden beloved by everyone, like you.’ Riddle looks pained. ‘I made a mistake…so I wanted to become someone like you, Leona-senpai.’”

This is different from how this same scene unfolded in the game, but there is still some unusual gentleness from Riddle where he says it pains him to see Leona wearing one of his collars and encourages him to confine himself in his room and calm down.

Otherwise game-Riddle does not seem to have the best opinion of Leona, telling Kalim and he and Leona are maybe unsuited to being housewardens due to being sons of wealthy families, and sympathizing with Jamil when Jamil doubts Sally’s claim about Leona being “a well-mannered young gentleman.”

Leona seems aware of Riddle’s strength, saying he,

“–can bust out a spell so fast it’s not even funny. And he’s got the firepower to lead a group and fight at the head of it. It’s a double-edged sword, considering his stamina and personality. But he’s had confidence as a leader for a long time, and that’s what counts.”

In an early vignette Ace scolds Leona for nearly letting Riddle get injured by a rogue spelldrive disc and Leona responds, “Riddle woulda batted that little disc away with his magic, no problem,” and Riddle agrees he was in no danger.

The two overlap during Fairy Gala IF, where Leona tricks Riddle into volunteering Ace for the job of infiltrating the gala by saying Riddle must be jealous of his dormmates, as his own have no initiative: “People like that could never handle this job. But my dorm’s different. I know they’ll get it done”

Riddle takes the bait, volunteering Ace for his slight-of-hand prowess (“Heh heh heh. This is a prestigious job that only Ace can do…”) while Azul observes, “Leona just played Riddle like a fiddle.”

Riddle and Leona also overlap during Book 5 where Riddle checks in with Leona about stage construction, and during Book 6 where Riddle uses Leona’s lap as a pillow for three hours on their way to STYX.

Leona refuses to let his club members steal a lanternblossom from Riddle’s team for their Vargas Camp task, and the two have been shown at least twice looking equally exasperated with Crowley.

In Book 7 Leona describes what may have been his first time meeting Riddle, saying,

“Not even a week after the first in-person housewarden meeting that school year, the original Heartslabyul guy was gone and Riddle came to greet us as the dorm’s new housewarden, lookin’ like a kid straight outta elementary school. I may not bother rememberin’ much, but that’ll stick in anyone’s head.”

After threatening to turn the house of Riddle’s dream into sand Leona is collared by Riddle’s magic for the second time in the main story. Leona deduces that Riddle has long since been possessed by the darkness but that he also must still be in the house, and when Riddle begins to cry—nearly drowning Leona’s group—Leona says they will get him out.

When Chenya asks if they really want to wake Riddle up despite how doing so will erase all the false memories of his family and friends Leona responds,

“No matter who’s tried to prune him out, he’s kept on growing, those sharp thorns stabbing through anything in his way. You wanna let the monster that managed to collar me not once but TWICE wilt here?”

It is Leona who approaches Riddle with the information that he is trapped in a dream of Malleus’ creation and Riddle nearly believes him, but is talked back down by a dream-Cater and dream-Trey.

After watching Heartslabyul student of darkness cheer Riddle as their Housewarden Leona asks, “What’s so great about getting fawned over by illusions of your own making? It’s gotta make you feel empty inside, right?,” but Riddle responds, “It…makes me happy.”

When Riddle awakens from his dream Leona says, “I’m hurting all over, and I’m running on fumes magic-wise. You really made me work for this,” and Riddle responds, “Leona, Silver… I fear you’ve seen me at my absolute worst.”

After Riddle is swallowed by the abyss of his dream and Trey begins to panic Leona says “(Riddle is) capable of handling whatever wild stuff may or may not get thrown his way,” calling Trey an over-protective parent (Trey: “As a Heartslabyul student, I’m proud to hear Leona give Riddle the credit he deserves”).