okay for your ACTUAL QUESTION...

It's still a bit early to know absolutely everything they intend on doing with BloomFES but from a cursory glance... I'm going to assume they intend on matching one character with another, and have them follow a similar story beat theme. Unfortunately, creativity is not my strong suit. I'll 100% be totally wrong, and as future focuses come out (Nene5 lol) I could see these shifting wildly.

Tsukasa: I think I'd like to see something with Tsukasa where he's really like, proud of how far he's come. I think he should have some pride or revel in those feelings and to be able to affirm himself. With his part of the current three-stage training arc most likely complete, a focus on mind in Filafever and a focus on body in Detective Tenma, I think he's in a really good spot for his skills. Though I'd like him to get one more focus first where he puts these newfound skills to usage so the FES card is more of a continuation after that. As for who could match this, I think a lot of characters could work, but I feel like Airi could be a nice one for lim diversity. Alternatively if the leaders-VS theory is true, it'd be Kaito.

Emu: As for Emu, I'm honestly a bit stumped. I feel like her first FES card sortof already fulfilled the type of thing I'd want for her and more. I love the focus on her family and I love her story having her reunite with Rakunosuke in a way. It was genuinely incredibly moving for me personally. I don't really know what angle they'd take with her next, though. I think I'd like for it to be a bit more chaotic, but in a controlled way. Emu is able to show her perspective now and communicate much more easily. I think her first FES being down to earth and grounded and emotional, while her BloomFES taking this type of approach could be exciting. As for who she could be paired with... I dunno. Mafuyu, maybe? Communication/expression...? It would be a pretty decently sensible pairing though, so maybe they'd avoid it.

Nene: I think I just want to wait for Nene5 here. She hasn't had a unit event since Hakoniwa and a LOT has happened in WxS's plotline, including the arc ender with the answer to the disbandment question, and so far the training plotline hasn't really touched on her like, at all. I think right now, she's an open ocean of ideas. Just don't be a fucking Myst card I will be so upset if it's another Myst lim lmfao. Just don't pair her with Ichika or Akitoya and I'll probably be satisfied... probably.

Rui: I want Rui to have some sort of reference to the Asahi plotline tbh. IDK what else besides that. Some sort of "This may be great, but I want this?" instead? Maybe he could be with Shiho? I think he'll be one of the more interesting BloomFES cards, gut feeling.

Yeah, I recognize my ideas are very vague and minimal, I'm usually not the type to have a strong "desire" or things I really WANT... I'm good at what's there, not what isn't. Sorry if some of these ideas aren't all that well written out. But it's fun to think about Bloomfes--honestly I hadn't even really considered it before now lol.