Those two... were more than a passing fancy, I would say. :3c
I spent a handful of months exploring the territory. Umm, emotionally, mentally, mostly, but still. Played and replayed DLC for them, ruminated a lot... Then developed headcanons, looked at fanart, conceptualized things for my own art... It might take me AGES to actually do but, I would like to write fic of those two someday, as well...

I'm not sure what I could say that is different from Avvy's rambles about them in the past, but. Umm the process of becoming invested in them was quite funny, because I spectated a friend of mine shipping them... and while being a bystander, I remember thinking 💭 that Kieran is quite... unstable, huh.
I guess, based on their initial demeanor, you would think Carmine was the louder personality?? But I saw fleeting screencaps that seemed to have the boy wiling out. Which, was objectively interesting. So I went into the DLC curious to see what was going on there...

... it was more unhinged... than I thought... I GUESS the thing about SGZI, is one expects to find a basic oneeshota situation going on here. Some dark-haired siblings... sure. But then like, they're both kind of like, social flops, umm, pariahs of their town. Not very graceful... these two... A burden unto Mossui. You start to wonder what's lead to them being this way. Why does Kieran cling to Carmine's side, hover behind her like a shadow, yet also whine about being fussed over...? Why is fussy ane so tolerant of mopey otouto... ? Why does he identify with the? Villainized depiction of The Oni and why does he regularly run up a mountain to crawl into a cave...,,.,., It feels like the DLC awkwardly grinds to a halt at times as characters try and teach Kiki about consent and how he can't just have ogerpon. But this makes him like insane or whatever and he can't actually take it. Then you get the second half of the arc which is like . Oh he's really crazy like really really... crazy. Ok. It's odd to see the siblings almost enter a bizarre role reversal, where Carmine is more meek and deferential, and Kiki is taking charge... Umm red flags everywhere... Yabe...

I guess it's kind of entrancing, how much of a 'wreck' this all is. Kieran's breakdowns, quirks, Carmine's clumsiness in contrast with some vanity, a lack of boundaries, everywhere. They don't seem like they're ready to 'grow up' and 'leave town' at all... Which is what I like about them. The game events should be about Kieran making a friend and meeting a mystical pokemon he's always been curious about... but instead he, quickly feels insecure, betrayed, and bitter.
There's of course the legendary line... where he's talking about how protag has everything he 'wants'... 'Even you, sis.' Of course, I love it in JP... ねーちゃんだって！！ (For a while I was having fun pulling up various letsplays and seeing how people reacted... One of my favorites is this guy who reads the line and, kind of beffudled, repeats, neechan...? It's very good.)

I'm speaking sloppily, mostly trying to convey my general affection for them. I Think About Them. Now an attempt at more organized thoughts n HCs n whatall...

I believe the situation with their parents is unconfirmed, probably little to no mention whatsoever about them, nothing we can draw conclusions from. [me voice] I can't help but feel as though it was a negligent situation... I like to think that they first had Carmine and made an 'attempt' at parenting, staying with grandparents for advice and support... but then, relied too much on that support, being rather hands-off with her once she could walk and talk. Then Kieran is an unplanned pregnancy, and at that point they are fully checked out. This results in Kieran not really getting much direct attention, not being held or reassured much as a newborn, which leads to him being a very sensitive, easily distressed baby. Crying a lot and being difficult to put to sleep... The sort of high maintenance that jiichan and baachan just cant keep up with.

So from a young age, I think Carmine sees her brother as quite helpless... Basically as far back as she can remember, he's needed to be shushed to sleep and brought all his favorite things to calm down. Yosh yosh... But of course, I like to think that he clung to her immediately, and it made her very easily feel like the Bestest big sisser evar... Add a little praise and encouragement from adults, and you have a Carmine very confident in her abilities. Umm but unlike say a, Mari-chan, I think she also could be mischievous and tease Kieran, purposefully make him cry and whine, be a bit of a bully. It's a particular flavor of the two. It's just endearing how dramatically Kieran will pout, umm has the saddest eyes you ever saw. But you can bring him back from the brink of despair with a lollerpop.🍭 This goes on uninterrupted for years...

It entertains me that Carmine is self-aware enough to say that Kiki has a bit of an 'ego' despite everything. I think she can observe that ego up-close... He's a sore loser...! He wants to impress, which is an interesting paradox because of how quickly he will shrivel over the tiniest thing. Still, he's um, passionate at times, can be stubborn, or seem like he's about to burst. [thinks] like when kittens tremble as they eat meat for the first time...
She always expects him to be clinging, whining, 'a handful', her responsibility.

[becomes haggard trying to word this...] I think Carmine has felt beloved for a lot of her life... Despite the situation with their parents, and the people in the village finding them unruly... I think it's how she manages to feel so confident about her looks, and capability. I think, um, she IS pretty, and Kieran so obviously... adored, fawned over her... It didn't matter much what other kids thought, said... She's also been able to, flip her hair, make teasing comments, boast about herself... and had a little boy, with shiny boo-boo eyes, gazing up at her... clinging to the edge of her dress... Wanting to hold her hand... get a kiss goodnight... It's given her a kind of delusional confidence. But I don't think she asks for 'more' than what she has with him...
I like her position as Briar's assistant, and that she does pretty well in Blueberry. I think of her attendance to this, far-away fancy academy, is Carmine putting in the time to set-up her life, so that she'll always be reliable and stable for Kieran. She's on a steady path... She's not actually wholly prioritizing herself with this, it's moreso about doing what she has to, as the older sibling. Figure she is there under scholarship, and works hard for it... Though erm, not actually there for, any kind of hobknobbing, and not really aiming for a grand position. Always think of her like a TA... Working with a professor and researching pokemon feels like a noble living, not glamorous, yet something valuable, probably pays well... What else... I think her shaking angy hands are cute...

On Kieran's end... I think the world feels filled with insurmountable tasks, without nee-chan plowing the way. Erm, I think he's not good at being... conscious or grateful... for what he has... So he feels very low about himself, and very frustrated with that sense of lowliness. I do think of him as subconsciously suicidal and prone to attention stunts, and that's really what's at the core of his identifying with the Onii and running up the mountain. He feels other, Unwanted, and it must feel relieving to take a physical action about it — endangering self AND receiving the comfort/coddling that is being dragged back home and overseen by nee-chan. There's an itching for, a sense of power as well, I think that's also what's appealing about the onii... The misguided view of ogerpon as something terrorizing is alluring to Kieran. He would like to see himself as something that others wrongly judged... yet holds a kind of menacing potential... With such extreme feelings of patheticness, you'd need to offset it with extreme CONTROL. I think obviously pokemon battles are another way to gain that sensation, and why he wants to prove himself so badly as a competent trainer. I think the, raw technical aspect of battles, training, is very intuitive to Kiki — so it could be his gateway to 'success'.... But prior to the DLC, he's still held back by social deficets, lack of motivation... I don't think he's very cut-out for school...

IMO, his sudden vault into Champion during the Indigo Disk, is a result of Kieran losing anything grounding him. So he can forego any modicum of, self-care, regularity, in favor of going all in with training, battling. This is a guy who is not sleeping, showering, feeding himself hardly. But there's no one to stop him from doing this to himself... Push self to limits! Doing exercises, like running on treadmill... doing crunches... enjoying aching sensations this produces... Enjoying the bite of hunger at times... It's all punishing but rewarding. Mm I think he also swaps tics of, fussing with his hair and touching his hand to mouth, but it just manifests other neurosis... Tapping foot, suddenly jerking and clawing down chest/collarbone (rake fingernails against sharply..) Biting inside of mouth... eyes held wide, twitching, jerking head...
Unwell unwell unwell unwell... scraping by... Though in doing all of this he can become a kind of laser focused battle machine and just claw way to top of school. Kowai. A show of... 'self control', just sharply reinventing himself, changing his demeanor. It's proof of something he's capable of and it's satisfying to see others be shocked by it...

Of course, I think a lot of this is unchecked mental illness and puberty. And ummm he could never really keep this up...
However he crash n burns, it's fun to think about. :3 Before canon events, after, little diverging paths...
For Carmine I think she's quite helpless to watch the Kieran she knew basically 'disappear'... I like to think she's really trying to, cajole him, offer him things, get him to engage with her. Lowering self steadily. Helpless, about it all, it's where nee-chan isn't the strongest... Want to bait you with treats. [sob] Subsequently though I think it's such a good setup for ummm sex... Like Kieran demanding this, with or without words, coming to expect it, and her just buckling. Umm rape is good here... Many dubious things. :) IT'S ALL BEEN BUILDING UP..............!!!!!!!!

[waves hands] And then oh you know... [smiling placidly.....] I also just like to think about horny chicanery and things happening in less loaded context... Or, um, angst, scenarios, where Kieran gets very injured or falls ill due to his mountain adventuring... Your good ole fashioned caretaking... doting, feeding, bathing brudder... Festival times, filled with warm memories... Training pokemon, admiring one another... Mundane things like doing stretches... They're just cute... in many contexts... (^人^)