Why I think Himeko Nova isn't our Himeko: A Theory & Prediction
I've seen a lot of people being upset about how she looks younger so here's a theory on why I think this isn't the Himeko we know now, and instead (fitting with the preexisting themes in planarcadia) a past Himeko from 15 years ago.
First of all, we know that Himeko was supposed to die a long time ago from Graphia's lineage curse. We also know that Himeko won the games 15 years ago, but she's never really recognized as a winner (and you would think she'd be really famous after only 15 years + the Fluffy and AE's popularity, but it hasnt been mentioned. Himeko was able to get rid of the curse somehow, and thus our first thought would be that she used Aha's minute of power to rid herself of the curse, but a Graphia descendent tried that once before and it didn't work, so how did she do it?
I believe Himeko, in line with Planarcadia's themes of duality/separate selves (Sparxie, Ashveil, SW999+Blade), split herself into two somehow (whether by manifesting a second self, splitting herself, or any other form of this). One part of Himeko went onto the AE and became the Navigator we all know and love, and the other part remained behind in Planarcadia, sealed within the 'World In Canvas'. This is how she survived as the curse didnt progress within the world in canvas, since we know Graphia (who lived thousands of years ago) is alive in there since Evanescia tells us that. We also see parallels with Eva being sealed in the Phantasmoon courtyard + her immortality, and only waking during the games (aka a rush of wishpower). This other part, whos dormant in the World In Canvas, is Himeko Nova.
My 4.4 prediction is that Himeko will parallel Fulwish, a fellow survivor, by drawing attention and wishpower to herself as a protector/hero/former winner, which she will funnel into Himeko Nova, creating a manifestation of Planarcadia's people. Himeko Nova's splashart has a lot of the symbols of Planarcadia's protectors, such as the Magical Girl Squadrons and the mecha (which both represent the past/future of Planarcadia, duality again). Her hair dissolves into stars at the ends too. Himeko Nova, as a true symbol of hope and perseverance for Planarcadia, will defeat whatever big bad we're gearing up for with the combined power of all of Planarcadia channeled into this hero. This parallels Fulwish who left Planarcadia once (just like Himeko) and returned (like Himeko) but was too betrayed by Planarcadia, thus creating the monster we battled in 4.2. Himeko, however, instead of having fake friends that tricked her, had a real family, and was able to overcome her past and channel Planarcadia's star hero in Himeko Nova.