I like the idea that the Steve’s all found Saber to be a bit..uncanny in their eyes.
My hc/depiction of Steve’s have always been these sort of, half dragon people, people who are magical in a sense. Markings that show off which chromatic/biome faction they belong to or which creator designed them. Different wing types, tails, ears, horns, even eyes.
But Saber? Has none of that, his skin is bare of any scales or micro feathers to form markings, he covers his eyes with a piece of clothe, his colors are odd and mixed, he’s almost like a cryptic to them? A being that looks like a Steve, but isn’t one.
So Shadow Saber takes on quite the horrific appearance for most, any who where survivors of the main attacks on their kingdoms would spread stories about this dark being who looked like them but wasn’t a Steve. A boogyman if you will
(And if the Red Steve’s where known to the other kingdoms at this time, they would have seen a similarity to their own kingdoms ‘boogyman’ and ‘a haunted suit of armor’ but that’s a story for a different time)
The only beings that could even match the freaky levels are creators, or Demi gods. As Saber calls them.