I think this AU is pretty cool

Being one of the first to get popular, it does get overused and often overshadows other swap AU’s but, it is the most logical one

Underswap takes the concept that every character has a clear counterpart and swaps them, witch is cool… most of the time

Some of the swaps simply don’t make sense

Temmie and Flowey are never mentioned as even remotely a pair once, although this still makes little sense, as temmies are cute little scrunklies and Flowey is NOT

But uh… asriel and monster kid???

What

Like the only thing they have in common is a similar height, but whatever, I can live with it

All in all, I give this AU a 9/10

Pretty cool, with a few minor flaws