Grim will sometimes seem intimidated by Leona (“When he looks at me, it makes every follicle of fur stand on end”), but this does not stop him from insulting Leona anyway, and he accuses Leona of bullying Azul in Book 3.
(Leona: “You’re the ones who told me to turn the contracts to sand”)
When Kalim insists that Leona made an effort during Fairy Gala Grim says, “I’d bet thaumarks to tuna cans that Kalim and Jamil carried the whole thing.”
The two characters overlap in a vignette where Grim spills a potion for a class project with Epel on the floor after bumping into Leona in the hall, blaming Leona for not watching where he was going.
Leona eventually decides to remake the potion for them while Grim actively insults him, saying, “It seems impossible for a putz who’s already gotten held back a year…you’d better not be sleepin’ on your feet while we’re in panic mode.”
When Leona produces the potion Grim’s immediate response is, “He probably just threw some random stuff in and called it good!” and when Epel confirms it is legitimate he says, “I know you, Leona! You totally used some secret cheat!”
Despite this, Jamil observes during Book 7 that Leona seemed truly worried about Grim.
Leona insists he is not, but Jamil appears unconvinced.
Grim comments that Ortho “is so nice and wholesome, it’s hard to imagine he’s related to Idia at all.”
The two only rarely overlap, with Grim eating a flower that Ortho attempts to show him and refusing to allow Ortho to scan him.
There is an as-of-yet unproven fan theory that Grim and original-Ortho may have overlapped in the past.
Twisted Wonderland Reference Note 