any thoughts/headcanons about celeste x ryoko? personally i think ryoko would forget "celeste's" name and starts calling her taeko, much to celeste's dismay ajahdjshd
on a serious note, with how narcissistic (imo) celeste is, she kinda would use ryoko as an ego boost. idk if that makes sense but when ryoko was junko, their relationship feels like a chess game or a poker match to me, with celeste being the one that has her moves figured out too fast. she wants junko's approval, her affection, her love, or any kind of vulnerability that would have celeste come out one step above junko. and with junko being junko, well.
and ryoko wears her heart on her sleeve. she's extremely vulnerable, and ryoko would be the ace up celeste's sleeve in their hypothetical poker match, the confirmation that junko does indeed care about her, the emotional vulnerability that celeste could exploit. she does love ryoko/junko back but imo, celeste's biggest flaw is her inflated ego—it gets in the way of her trying to form any attachments—and she would use ryoko as a way to get back at junko.
I have finally, finally gotten to answering this after days of saying I would! Oof, so sorry it took me so long.
But I really like this interpretation! Of Ryouko being confirmation to Celeste that Junko does love her, and having the emotional vulnerability that Celeste craves that she doesn't get from Junko. I think she would like this two fold—because I think Celeste does want to be cherished, so... Ryouko unabashedly cherishing her would soothe that part of her. But as you said... she also likes having some degree of power over people, especially because the Junko/Celeste dynamic is such a give or take where Junko holds all the cards (I'm invisioning Celestia and Junko as sort of... locked in a battle of love. Sort of like Kaguya-sama love is war, where both of them are sort of in a competition to make the other be vulnerable with them... only saw the first episode of that anime, but—something like that is what I'm envisioning) and Celeste is left scrambling. So Ryouko would be... extremely validating for Celestia in multiple ways, and I do think she'd sort of get back at Junko with Ryouko; lightly bullying her at times.
Part of that "getting back" at her is just. Well. Making her admit she loves her, which Ryouko does easily and freely, not knowing it's supposed to be a secret she keeps close to her chest. And Celestia loves that. I think where it becomes hurtful to Ryouko is the fact that Celeste never does the same, but... I actually don't think Ryouko would mind that much, because she never minded with Yasuke. She even appreciates that Yasuke doesn't offer her pity like others do. Ryouko has unreasonable faith in love. She knew as Junko that Yasuke loved her, and that's something Ryouko never forgets. She brushes off all his cruelty because she knows instinctively that it's hot air (to some degree). What makes her upset is when Yasuke doesn't believe her when she tells him she loves him. Being denied her own feelings, her own lived reality, is what upsets her. Because the feelings she remembers are the only thing she can trust in her world. More than that, those feelings are her whole world. She can't believe in anything else, because she doesn't remember anything else.
And that's... kind of how she likes it. Ryouko and Junko are both afraid of the world, of the despair of the world, it's just how they deal with that that differs. Junko choses to embrace that despair, so it can't truly hurt her. Ryouko chooses to forget. To run. These are both born of the same thing—fear. Ryouko instinctively knows that... if she let the world in, it would hurt her. In a way, it always does; everytime she forgets about the world, that's the world rejecting her. It hurts. But that's paradoxically why she embraces forgetting it—because it means she'll forget that it hurts. And... Yasuke is the only exception to this. She loves him, and he's all he remembers. So that's the only thing she can have faith in. Her only connection to the world. She clings to it, because it's all she has.
But. It also means he's the only thing that can hurt her. And that's why you get her breakdown at him in DR0, with her begging him to make her forget about him. Because Yasuke is the only thing she cares about, and that means he's the only thing that can cause her despair. If she forgets about him, she'll be entirely free from despair. From the world she thinks is inherently cruel. From the world she fears. That's why she doesn't want to remember. Because then, she'll have to care about the world, and that hurts. She'd rather it have "nothing to do with her," so she forgets. Ryouko is just as contradictory and twisted as Junko in that way; because forgetting hurts her, but if she forgets, she'll forget even that hurt. That's why she clings to Yasuke; he's all she has, and if she loses him, she'd have nothing. That's why she wants to forget Yasuke; because if she has nothing, she can never be hurt by the world again.
It's the exact same reason why Junko embraces despair.
(Well, of course it is. They're the same person.)
So. How would this relate to Celestia/Junko? Hmm. Well, I think Celeste would have just as hard a time getting under Ryouko's skin. Because, while she's winning in the sense that Ryouko is being vulnerable and honest, Ryouko... doesn't actually see this as a competition at all, in the first place. She also would have faith in Celeste's love and disregard her words, because, like... she knew Celestia loved her as Junko, too; the fun was just getting her to admit that. So... Celestia's bullying wouldn't... bug her that much. Maybe she'd theatrically mimic upset, like she did to some degree with Yasuke, but... that's more of a game to her. (Even if she somewhat means that upset sincerely.) I'm thinking specifically when Yasuke would call her ugly, she'd basically be like "I'll fix it!" which she meant, but she was very theatrical about it, and wasn't actually that upset, because she knew even if Yasuke found her ugly sincerely, he'd still love her. So: sincerely miffed about being called ugly and willing to "fix it" to accommodate Yasuke's taste, but also not deeply upset about it because she deep down knew he'd love her anyway. Playing it up to some degree because it's banter, and that's what they do, that's how they have fun. Ryouko isn't really taking his words seriously, and neither is he. (Which is kind of the foundation of what upsets her later on: she doesn't realize some of what he said is meant sincerely, and she's upset when she realizes that he also didn't take the foundation of their banter- her love for him- seriously either. Ryouko knows that Yasuke loves her, so he doesn't take his hate to heart, despite that hate also being sincere. She takes their banter as unserious, even though Yasuke's words are founded on sincere feelings. Similarly, Yasuke doesn't take Ryouko's love seriously, because he doesn't believe in it—he thinks Junko was only using him from the start. So he doesn't take her banter seriously either, even though that was also built on sincere feelings. Which... upsets Ryouko in that breakdown scene when she realizes. Only for her to forget that hurt again, which.... means this conflict is never solved.)
So I could see Ryouko just... brushing off everything and treating Celestia's power plays and teasing as... just a game between them, as banter. She wouldn't take the base of them seriously either, and she... wouldn't really be bothered by it. So... Celestia is left trying to win a game they aren't playing. Combined with Ryouko calling her Taeko, Celestia could eventually find the whole thing very grating.
Because she IS winning against Junko, but Junko isn't even there TO play, and Ryouko is playing something completely different. If Celestia was playing chess against Junko, Ryouko is playing checkers. They're just not operating on the same wavelength anymore... which could paradoxically make Celestia insecure, which would make her seek even more validation from Ryouko.
Ryouko on her side is like... wow! Taeko really likes it when I tell her I love her! She must also really love me to want to hear it so much!
So Celestia is not winning the checkers.