Wut is Subtale about OwO
Sorry this took so long, lol
Subtale is basically just a roleswap AU but a bit different from that. Above may or may not be 3 of the canon role changes.
Unlike Swap AUs, Subtale relies on things my friend Sam calls 'Loops' as you can probably guess a loop will start with someone and 'end' with a new person, the person at the 'end' will then change roles with the person at the start while the person at the start will change roles with the second person, who does this with the third person, who does this with the fourth person and so on.
Because of this role-changing chaos, bonds are broken between characters and new ones formed. The drawing above is one of the results of said chaos.
Characters will take on their new roles but will keep their personalities, like Ence who is now the lazy royal scientist and Temmie who is now the owner of a bar which results in many fights between customers.
Some changes have made grudges form between characters, Mettaton being one of them. The story doesn't change, so some... fixes are made for which character deals with an issue or how an issue came to be. As I said earlier, bonds have been broken so...