How about Arataki Itto?
Itto is canonically the most gluttonous boi in all of Genshin. He literally got kicked out of a buffet for eating EVERYTHING in the buffet. So, with how gloriously shameless Itto is, when this studly young oni burps, it's gonna be the loudest, strongest BELCH you've ever heard. And Itto's response is gonna be to slap his bulging belly and smack his lips shamelessly as he caresses his overstuffed gut and groans about how tasty everything was. He's also a massive showoff and boaster, so of course, he knows how to burp on-command is all too eager to get into burping contests to boot.
After stuffing his face:
"WHEW! (slaps his big belly and burps again) Gruooohhh now THAT...huUrp...was a meal!"
(smacks his lips contently as he caresses his gut) "Hohoooo man, I'm STUFFED...dude, this place really IS all ya can eat, huh!"
"Yooooooo...did you guys FEEL that?! Haha! Think some plates actually rattled on that one!"
"Phew...that was a BIG one, huh! (gives his belly a few firm smacks) Nothin' but the best outta the One and Oni, am I right??"
"Hahhh...(lets his tongue hang from his maw as he strokes his belly) ...Think I just made room fer dessert, hehe..."
"Ahhhh, haha...that felt amaaaaaaaaazin'..."
"What? That's how I compliment the chefs! Hafta burp loud enough so they ALL hear, right? (patting his belly in a showy manner) Feedin' THIS oni is a team effort, after all."
"Ohhh ho hooo man, talk about a GUT rattler..."
"Oof, heh, bet they heard that outside the buffet...! (grins a fang filled grin) Least now they know the grub's legit."
In a burping contest or showing off:
"Whew! (smacks his gut in a satisfied manner) That one had some HEFT to it, huh!"
(smirks) "Oh, ya thought THAT was impressive? Nah-nah-nah-nah, ya ain't heard NOTHIN' yet...(takes a few big gulps of air, then pounds his chest once as a MONSTROUS belch explodes from his maw)"
"Ha! Let's see ya top THAT! Bet'cha can't, can ya?!"
"Ohhh yeah, ain't nooooobody bestin' the One and Oni burp champion of THIS gang!"
"Mph, still got some left... (kneads his stomach and lights up eagerly) Oh! Yo! Check this out! I been practicin'! (takes several big gulps of air, and starts beat-boxing with his burps)"
"Haaaahhh, almost made myself DIZZY with that one, haha!"
"Ahhh...(pats his stomach)...even on empty, those feel sooooo good just lettin' rip like that, ya know what I mean? Pfft, course ya don't. Ain't no WAY ya ever let out a monster like that one, no offense."
"Pfft, that was a five at best. Here, lemme do a better one...(takes a deep breath and grabs his gut as he belches ferociously)"
"Ahhhh, was that childish'n crude? No doubt. Is that old lady pissed off? I mean, she's brandishin' a knife and pointin' it at me, soooooo...no clue. Was just lettin' rip the greatest burp of all time satisfyin' as hell? Uh. Hell-eeeyyyaaah, baby."

















