After doing Saviour run, Barrier broke, Monster-kind was freed... and now you are back to SAVE Menu... There's were two options Continue and True Reset However once you shatter True Reset button and reach out to Continue button, Suddenly Asriel a.k.a your ghost assistant that was fused with your SOUL, stopped you as he spoke in worried tone...

Asriel: I think, someone's in our SAVE Menu

However once you turned around, you see Seraphim-like Giant Familiar Skeleton, as he looks down at you as he pats your head with one finger, seemingly proud that you didn't use reset button and even broke it. He then presses on continue button as he waves his hand, as he spoke.

Seraphim Sans: goodnight and don't be afraid of me, human