Based on a Korean Author named after this page. (otherwise known as: Gram Parson.)
The characters they make are primarily smash bros but chibi. Not unlike those "JUS" characters.
Go here for more information = https://mugen.fandom.com/wiki/Sumin

These characters (If you see created) are meant to be close to the gameplay style as close as possible.

Yes ofc.

But I may now consider them as a Legacy.

Not by the real deal.