To keep riffing on my Riche thoughts for a moment, it seems significant to me that the first time we see her really step into the action in some way other than asking for help, her contribution is via acting. And specifically acting in the arc themed around the idea of "the self" and "personality" (in addition to social structures) as performances.
Furthermore, despite not being the performative/theatrical type in daily life, Riche turns out to be a pretty decent actress! Especially compared to Noé's stilted performance, which Mochijun places her in direct contrast with.
This is a somewhat. conspicuous character trait to establish at this particular point in time.
Shifting over to pure speculation, if I'm right about something Bad happening to Dante during this arc (which I realize is a really big if), I'm fascinated by the prospect of what might happen with Riche afterwards. If things do go that way, there's no way Johann's going to carry on business as usual in the aftermath, which means that poor Riche will suddenly be the only one left from our original dhampir trio.
If something like that does happen, I'd love to see Riche step into a more plot-relevant and leaderly role. The younger dham kids (assuming Mochijun doesn't go on another orphan-killing spree) are going to need her to step up and continue what she, Dante, and Johann have already been doing for them. They'll need a leader and protector and someone to interface with dangerous outsiders like Machina for them. And Vanitas will also need a new primary information broker. Who better to fill those roles?
And going back to the whole "Riche's apparently a decent actor" bit, given how thus far she's one of the only characters that doesn't put on any sort of affectation or cling to any denial to hide her "true self," it makes me wonder what that latent theatrical competence might be put toward in the future. She hasn't been using her ability to act for much up until now, so why draw her into the spotlight and establish that skill? To me, the obvious answer is that it's establishing something that will become key for Riche later.
If she does have to step in and start to fill Dante's bigger shoes, the ability to act and put on the type of protective mask that she's never needed before would do her a lot of good.
