In Volume 4 Tyrian remarks that Jaune interests him (or something to that effect). He looks down to his shield briefly while saying this. Given that Jaune is now a mythological character *in universe* (lol) perhaps Tyrian read about The Rusted Knight in "The Girl Who Fell through the World" and, well, someone who looks like an older version of Jaune is described. Maybe by chance his description also includes this small detail of the emblem on his shield (the two moons/arcs).
Does this sound reasonable, and more importantly could this idea have any significance if true? I for one am entertained by the notion that Tyrian is a mythology nerd.
Yes, the Tyrian remark is one of those dreaded things because I've seen it used to support all sorts of theories, and I tend away from ambiguity and overt literalism.
To my eyes it's far too ambiguous in any way to set up a direct Rusted Knight thing (e.g. that Tyrian's twigged there is some myth afoot), because I don't even know if Salem knows about Ever After. That is to say, it would be much more reasonable for Tyrian's character to assume the relation is only cutesy reference at best. I also have assumed all this time that Jaune's emblem is the family herald, so there's no reason not to suspect that it's simply because of his family name. Which, mind you, at this point in V4, Jaune as a character outside that stuff really started to develop.
I don't think it's reasonable to assume from a narrative perspective that Tyrian is setting up this idea of the Rusted Knight whether that is by literal awareness or dramatic irony. It's certainly only something you'd pick up in retrospective, and the implication that he knows anything about the Rusted Knight (for Tyrian, who serves a literal fairytale figure, it's not a terrible stretch he'd know) but also by extension is aware the Rusted Knight is real is a lot for me to assume. I'm not dismissing that this can't happen, but then the question I'd have next is: why? What does it achieve? I can't really identify what it does story-wise or even practically speaking (e.g. strategic set-up).
But I don't think it's wrong to assume there is some sort of strange Jaune-Tyrian connection. I really don't know what fashion it's going to eventuate at any point, but I've always wondered why their Semblances contrast so (Aura-penetrating vs. Aura/soul-touching) unless it's really just a matter of coincidence. It's also not lost on me that Tyrian is a figure who effectively encases Mercury (as a false father figure) and Jaune has some weird set-up related to a certain Fall Maiden's redemption arc, so I don't know if there's any connection there, either (since I contend Mercury will probably be saved too).
Of course the thing I'm curious about here is to what degree is there set-up for the current scenario with Jaune and with him permanently, basically, being the Rusted Knight - which does colour some of these scenes now, no doubt. I'm still ambivalent about the permanency of his current state, but I also heavily doubt that ascendancy works the way people think it currently works (losing all one's memories) since, well, from a purely practical perspective, they're not people of Ever After, and if Jaune's fears are affirmed, that's not really interesting character development, nor does it really answer what he's most fearful of about himself and the world around him. (Of course, I do think that he will be afraid).
So no, I am sorry to say that I don't really buy it, mostly because whilst it might be neat character effect (in my eyes, it's more to do with the fact Tyrian is the one most 'aware' of Salem's predicament, he knows whom it is that he serves - myth/fairytale is real) from an analytic perspective I can't really see it working or what it would serve. As it is with character dialogue, the foreshadowing based off of it is rather quite straightforward (or ironic), and it wouldn't just be doing Tyrian character work here, but also Jaune work.
Then, once you get into that - we know Jaune's aware of the fairytale in real life, and you'd think perhaps he'd recognise his own emblem. So that's where it definitively falls apart for me. But the whole idea is that he has to live it, and now he has a very different perspective. So I wonder if having lived out the Four Maidens fairytale, he's come to any different conclusion about Ozma, and I wonder if, say, given that there's currently a rogue Fall Maiden with a missing half of the story, if he'd have anything to do with that... oh, I'm getting off track now. I'm sorry, it all circles back to Jaune and Cinder eventually. 🥰
P.S. Thank you for your ask, hope you have a lovely day. <333