Mechalor AU Anon retuning to bring up a few things that came to mind.
1) I can imagine that Marx, due to having not gotten the Nova wish, would instead roll around on and attack with gem apples as opposed to his usual beach balls.
2) in Marx Epilogue, would the Ultra Sword sequence go differently on account of Marx not having hands? Maybe he uses a different Super Ability (Flare Beam as an example) or perhaps a different move entirely (Something based on the Crowns Cutters? A black hole akin to his splitting attack from his canon self?)
3) What happens to Nova after Magalors defeat? Its described to be "quietly whirring", so I assume it is just functioning on low power mode, but would it eventually fly away? Crash land on Popstar? Maybe it stays orbiting the planet, becoming a new background element (one that I'm sure would draw some attention from other worlds).
And 4) Would Mechalor, on account of him being reconstructed out of his magic and Nova's parts, be able to use any of his boss fight attacks without needing to deconstruct the god clock? Would he maybe even be able to make a wish on himself if given the needed power?
(Oh and 5) I feel like Mechalor "not changing from the experience" [being trapped inside Nova and having to pull himself together] seems a bit strange when Marx in canon changes from his own experience, even if it's a small amount. We don't see Marx try betray anyone, nor him try snatch up some other power source, but it seems like Mechalor still would. Idk maybe I'm reading too much into this.
6) (last one for real this time) what would the Marx Soul equivalent be? Magalors essence creeping into Nova and infecting all of it, remaking himself out of ALL of Nova rather than bits and pieces? Magalor just absorbing it's power as it explodes (assuming Kirby hits him into Nova's core just a little harder) and refusing to die, perhaps subconsciously making a wish to the last remnants of Nova? Maybe he isn't even strong enough to manifest one, and he simply *tries*, making a mess of magic, Nova pieces and himself that shambles towards Kirby, its one goal being taking them down with it.