Monsters react to the Underfell version of them?
for a minute there while i was writing i stopped at underfell after papyrus & switched to underswap for undyne before i realized that i’d switched aus for absolutely no reason other than that’s where my train of thought went whoops
His initial reaction is just “so who’s the edgelord.” After finding out that that’s supposed to be some sort of alternate him, though, he’s pretty worried. The guy seems eternally nervous, & it’s unlike him to act squirrely around his own brother, like he’s afraid of getting hit all the time. He works on trying to calm his other’s nerves as best he can, wondering just what kind of world this “him” came from. Hey, at least they both seem to like jokes.
He’s super impressed, his other self seems so strong & cool!–until he realizes what a bully he is. But he’s sure that what he just needs is a friend. After all, friendship is what makes him happy, so obviously it should also make…”him” happy! He ends up dragging his other self around, trying desperately to show him that he doesn’t have to be so grump & standoffish all the time.
She’s kind of off-put. Wow, she knew she could be rash & a little bit violent, but her other self is downright cruel. She doesn’t like the way her Underfell clone walks around like she’s some sort of ticking time bomb, always ready to lash out on the first poor unfortunate soul that crosses “her” path. She’s very on edge around her.
God, she’s jealous. Her other self is so confident, so strong, so assured in herself–she’s everything she’s ever wanted to be. Until she realizes that the reason that she’s like this is because she has no sympathy for those around her. Her alternate self puts the “mad” in “mad scientist” & it worries the heck out of Alphys. If this is what she’s like in that other world, then she can only worry for the fate Mettaton’s suffered at her other self’s hands.