What would happen if either BAON boys? Found themselves back in the respective universes? (Not knowing it was only for the day)
For a second, I thought this was asking about resets, and I’m pretty sure that would involve a couple of nervous breakdowns. Stretch in particular would not deal with that well.
But no, just ending up in the universe? I think they would actually hold up rather well; once Stretch got his thoughts in order, his first inclination would be to check on the machine. It worked once, after all. (I haven’t explored yet how they ended up in the Undertale universe, we will eventually, but it had a lot to do with the borders between worlds breaking down due to resets. Underswap went first due to multiple genocide attempts and resets, and after that it was like dominoes falling, with Underfell next and both of them crashing into Undertale.) His reaction would depend on the state of the world, too...Snowdin might very well be a ghost town.
Edge would be in more trouble based on the fact that Underfell is Not A Good Place. After years away, his instincts simply aren’t as sharp and also, he’s even less willing to gain LV than he was before, he doesn’t want to face Stretch with fresh EXP in his soul even knowing he wouldn’t be judged for it. Logically, the best thing to do would be to hideout and wait for a rescue attempt, but there’s no really good place for hiding in Underfell. Snowdin woods is filled with XP hunters and Monsters driven insane by their LV, and after so much time away, he’d hardly be welcomed back into Snowdin with opened arms. Snowdin wouldn’t have done well after he left, too. He’d be living a version of the Running Man until whatever it was sent him home.
