Board Thread:General Discussion/@comment-37750220-20181214063221/@comment-39394247-20190729021408

Terrace13 wrote: Oofoofoofoofoofoofoofoof wrote: Maybe because he breaks the game and such... but any other boss at LV 19 would be harder, as KR will quickly reduce your HP to 1. Undyne the Undying would be 100x harder at LV 19 than Sans - one hit is enough to reduce your HP to 1, and I'm not sure if you could ever win either!

[Fight]

8495823

How would Undyne be harder? She can’t dodge after all and since you are lvl 19 she’d probably just die in 1 hit.
 * But it refused.*

Even if she had KR (which she most definitely doesn’t), it’d be like the mettaton neo fight where you kill her before she makes a move. She can probably dodge anyway, and likely would if she was able to sense that Frisk was LV 19. And she might not even need to, unlike Sans.