Hi hey! Sorry to bug again but, the undertale Au, how can Rin and Len be “playing the roles?” if I can say, of Toriel and Asgore if they are twins? Is there some sort of elaborate backstory that happened if so then what is Kaito as “Sans” to the twins. Or maybe I’m just over thinking this. (Forgive my poor English)

QUOTING FROM ARIEL BUT,

Basically there’s no rules and the story of the mint undertale AU is loosely based but the characters are more of a personality basis than Undertale Lore basis– aside from Chara because that’s up in the air and dependent on the theories you subscribe to, but regardless

No rules, lots of fam stuff,

AND to be slightly more specific and going with that: Yea, there is backstory stuff that explains what goes on! 

I’m just– not sure if I wanna publicly ramble about it or not asdfds

I can understand the confusion though, so don’t worry on that— also your english is fine!

Why Rin look so scared? Has she met Will before??

Nope! But, well…

If your big sibling was in someone elses body, and a ‘mind is the plaything of the body’-type situation was going on… especially given how Will’s body kept the. Very, very far along corruption, which is specifically for the purpose of being an avatar for the otherwordly being responsible for BR, she has reason to be nervous.

That is Kai in Will’s body, she knows it’s Kai, but all of that I think would have anyone be at least a little weary.