it would have a more fitting design like Eternatus (speaking about annoying things: drawing it).
On a similar note, something that has always irked me about Eternatus’s design and lore, much as I may like it in general, is that I’ve never been quite sure as to whether the regular form is meant to be interpreted as “incomplete,” along the lines of Kyurem and Necrozma’s base forms.
What I mean is, Kyurem and Necrozma are literally broken, fragmentary beings. The base forms that we see are visibly “wrong” or lacking in some way. Kyurem is asymmetrical, frozen over, and emaciated. Necrozma is a jumbled arrangement of crystalline dragon bones, with its dark coloration owing to impurities that have built up inside it. Not only that, but we see how their fusable partners “complete” each of them. BW Kyurem look considerably more balanced and “full,” even if they are still technically incomplete. Meanwhile, Necrozma converts Solgaleo / Lunala’s entire body into photons in order to reconstruct the missing portion of its original form.
Eternatus
could be read similary, in that it’s basically just a big skeleton. Where is its skin? Where are its organs? Some of the characters in the story mention that Wishing Pieces used to be part of Eternatus’s body, which sounds very similar to Necrozma’s situation with respect to Z-Crystals and Sparkling Stones. So you could infer that the Wishing Stars are actually those missing organs… but is that actually what they’re going for? I’ve never been sure. For one thing, it’s a little gory, in a way — with Necrozma, we can deduce that the Z-trinkets were formed from Necrozma’s lost light being converted into matter (the reverse of what it does when fused to Solgaleo / Lunala), which is a little less gruesome than having, like, Eternatus’s hardened spleen strapped to your wrist. Secondly, while Eternatus
is just a big skeleton, which could suggest incompleteness… it’s also a totally alien creature, and I feel like it would be perfectly believable that that’s simply what Eternatus naturally look like. But
then the question is, what do they mean when they say Wishing Stars were originally part of Eternatus’s body?
One might suggest looking to the Eternamax form for some insight, but the characterization of that form has also always been a little unclear. Eternabeam’s move description says that it’s Eternatus’s “true” form, but the Dex entries describe it as Eternatus in “a state of power overload,” which doesn’t exactly sound like it represents regular circumstances. Though if the former is the case, I suppose that would answer the previous question — Wishing Stars are the parts of the Eternamax body that fell off when it was defeated by Zacian and Zamazenta, while the base form is the “leftover.” And it can regain that form by being exposed to energy from Wishing Stars (but apparently for some reason it doesn’t need
all Wishing Stars back in order to reconstitute itself, whereas Necrozma is likely compensating for the irretrievability of all the Z-trinkets by using the light stored by Solgaleo or Lunala as a substitute). If it’s the latter, though; the “state of power overload,” then I just…???
The Kyurem thing has always stood out to me as odd and going by the recently translated interview where they said that at first they wanted to fuse it with a strong Pokemon but not knowing which one in particular makes me feel like it had a completely different origin planned for it at first. It's a wonder the Tao Trio worked out so well for them if they really just designed an unrelated, incomplete grey dragon.
I’d have to double-check, but IIRC they also said something similar about Necrozma’s extra forms. That may just be how they prefer to approach things like that; sort of like, “We have some loose ideas for how we might expand on this Pokémon, but we’ll iron it out once we actually get there and know what game we’re making.”
But you can easily imagine the climax playing out exactly the same way even if those forms didn’t exist — while they are cool, they exist solely to provide flashy new designs for the boss battle.
