Ori not only wouldn't say it, but doesn't quite get the concept. Adult Ku might say it. The sort of thing that makes an owl the size of a tree curse does not come up often.
Iselda definitely uses "fuck" as punctuation, it makes Cornifer sweat because sweetheart, is that necessary? So do God Tamer and Lemm.
Someone sent me an ask, so here are my opinions on whether a variety of Radiant Historia characters would say fuck.
when the grumpuses in bugsnax say things like "thank grump you're alive" or "grumping why" that's narrative censor and they're actually swearing (also on snaktooth they're starting to swear by food...hence phrases like "scared snakless". culture drift!) E7+! can't have the funny muppets use english swears!
Aziraphale says "fuck" exactly once in canon. Crowley probably says it casually, and the "Go- Sa- SOMEONE" is what he says in situations of extreme severity because they have more impact than "fuck" for a celestial being (as they know for a fact the Someones in question exist and have to make an effort to be physically capable of fucking). The Dukes of Lurk probably have mouths as filthy as everything else about them, though I see them using various words in not quite the right context since their knowledge of humanity is a touch off.
Kiba says fuck. I was originally going to specify kiba inuzuka from Naruto, but I have decided it's every character from any anime that's named kiba, because I said so
Eda ABSOLUTELY says fuck. This is unambiguous. Luz says fuck occasionally—she’s not opposed to it but she rarely feels she has reason to use it! King SCREAMS fuck, daily Hooty does not say fuck but he could if he wanted to and might if badly provoked? Lilith doesn’t say fuck much but when she does it’s fuckin atomic Willow says it under her breath a fair bit when frustrated, but not a lot in conversation? Sometimes lets loose the BIG fuck when she’s super pissed Gus does not say fuck because he doesn’t know what it means and no one at Hexside will explain it to him on account of his babey energy. Amity says fuck fairly freely when upset or mad, but only occasionally in conversation Edric and Emira both say fuck with reckless abandon Everything Boscha says has been dubbed over to air on TV because otherwise it would not fly on the Disney Channel
Mato uses "fuck" for emphasis, and, being who he is, always emphasizes everything. Oro, not liking that kind of language, tried to institute a swear jar. Sheo, arriving after the initial incident, thought Oro was just trying to shake down Mato for geo. Now they all live as far apart as they can. Sly has no idea what happened.
read a fic the other day where the Radiance taught Hollow a bunch of swears out of sheer boredom when they were glued together in dream jail, and mangled their physical form to give them a functioning-but-painful voice for the same reason so the first and in fact only thing they've said in their post-canon recovery is fuck
I have created the only gacha game power tier list that has ever mattered: Arknights characters by who can, canonically, say fuck.
