too many questions (all shards? reminded me of GD -flowey.exe)

There are a lot of AUs, and even then some of them are not publicly listed, like SCPTale (my au)

1. Basically Infinite. The limit is the world's imagination.
2. The Knight is the guy you fight at the end of Chapter 3, duh
3. TO SAVE THE WORLDS, THERE IS ONLY ONE WAY; THE HEROES MUST FINISH THEIR PROJECT BEFORE MONDAY
4. Because reasons
5. Freedom (idk)

we don't see mettaton either but people are attracted to papyrus
lets be honest we prefer papyrus only because of the fact he is a walking meme

Papyrus is just too endearing. He cannot be ripped apart into a million tiny smiley bits and pieces

*papyrus turns into a million tiny dust particles in geno and neutral*

I actually have a theory about the shadow crystals:
If you collect all of them, seam will use them for some evil reason and seam will be the secret final boss.
Once you defeat them you either get another ending or and item that greatly facilitates the final boss fight of the game

Also i think it's important to notice how you can't have all shadowcrystals in the weird route