Snapped

Finally, after all these resets, it appears they finally got their "happy" ending.

However, not all of them feel the same way.

Flowey and Sans are the two left who remember what happened, and they are filled with resentment. Just the knowledge of the resets can be nearly maddening. However, Sans keeps his smile. But one day, he realizes...

He doesn't want to be Mr. Nice Guy anymore.