I think my problem with Shadow is we learn that he's a prototype of the Ultimate Life Form and was created by Gerald Robotnik, but then we find the ACTUAL "ultimate life form" and it's a giant lizard thing. How does your research take you from creating an anthropomorphic cartoon hedgehog to... that? On the same project? (maybe this was answered in Shadow the Hedgehog, I dunno)I wouldn't like that. The reason it wasn't addressed is because shadow's design original was just purple sonic with scars. Legit. So when the design was made better it changed so much that I guess they didn't bother changing the script and it became a meme. There's no need to try and actually incorporate the two, even the games took the one implication that they might be incorporated and threw it out the window. The two are separate entities with separate backgrounds and that's cool. If they ever get to shadow in film, all he has to be is some ancient hedgehog sealed underground. Or the government found him, his greivences toward the world and mental manipulation work while making his backstory leagues less complicated
As a kid I theorized that Sonic himself was an offshoot of the Ultimate Life Form project (his cryptic comments at the end of Last Story before the ever-classic "To the planet as cool and blue as me!" line seemed to suggest he knew more than he was letting on, though he could have just been thinking out loud), but I don't think it has to be that obvious (and dumb). Maybe Gerald, drawn to power, was studying the echidna tribe and happened upon this bad boy:
The echidnas worship the hedgehog as a god (which is why they chase after Sonic in the opening of this movie), so Gerald inadvertently creates Shadow in Sonic's image, not realizing the mural is actually a prophecy or that Sonic is a real person (well, hedgehog).
idk, just spitballing.