Copycat

Undertale truly one of a kind, no matter how many AUs or alternate universes it doesn't have any rivals that can compare to it.
Many agree with me, many don't, but we all know the same thing: you are never supposed to mess up an original, and that goes for Undertale too. Undertale is the original of many copies, so it's natural that people don't want to mess with it, but what if a major glitch happens in the original universe.

How will it affect the other universes?

Is it just a glitch, or is there something more to it?

Is there a way to fix it?

Well, you'll have to read to find out.