Ok, since the story of Air Riders makes so little sense to me and felt like a bit of a slap in the face at times, here's a completely random theory that I just thought of, regarding Zorah and Nova. I haven't seen anyone post about anything similar yet, and thought that while unlikely, it could at least be interesting:
Due to both of them presumably being ancient and existing somewhere in space for who knows how long... perhaps they've already met before? Maybe they're even old enemies...?
Zorah's design is very unusual and, dare I say, it looks almost incomplete. When I first saw it in the cutscene where it flies through space before hitting Popstar, I felt like all the dangling cables at the bottom made it resemble... a severed head of a much bigger machine. Zorah becoming Gigantes might not have come out of nowhere. It might have originally been a machine built for destruction and devastation. Until someone, somewhere far away, ultimately defeated it and destroyed most of its body, leaving only the head/core to aimlessly roam the cosmic void for what seemed like an eternity. At some point, Zorah might've posed a threat to Nova in some way.
Finally, Zorah lands on Popstar. At this point, it might regret its past actions or not, but that doesn't change the fact that it's in a horrible situation now and only wishes to be able to move again. Its wishes finally reach the Fountain of Dreams and then Nova. This is where the clockwork star realises what situation its formerly dangerous enemy finds itself in and decides to come up with a plan: grant Zorah's wish (because it must be done since that's what Nova's programmed to do) but also use it as an opportunity to finally get rid of Zorah once and for all. The plan goes as follows: turn Zorah back into the threat it once was, so the inhabitants of Popstar see what really landed on their planet, but take away Zorah's free will so it doesn't actually communicate to them that it might not intend on harming them.
Nova's plan was never to destroy Popstar with Gigantes, it was to render Gigantes capable of destroying Popstar so our heroes would feel threatened enough to destroy it, without it ever seeming like Nova had anything to do with it. Therefore, the clockwork star would avoid any risk of misinterpretation of its goals. This plan would've worked if not for Noir Dedede creating itself and ultimately ruining it all for Nova, in the end resulting in the clockwork star being seen as an evil device attempting to destroy the planet for no reason.
Note that this theory only assumes that Zorah used to be evil but might not be anymore (probably isn't). Either way, Nova would have no way of knowing about its potential change of heart since its wish came to Nova indirectly, and so Zorah couldn't have explained anything even if it could and/or wanted to.
This isn't a theory I'm really planning to do anything with, but it was fun to come up with an explanation, that in the best possible case actually features no real villains. Only misunderstandings and tragedy (the ol' Kirby special).
