Victortale

It has been 8 years since the barriers destruction. After that Frisk has destroyed the reset button for good, flowey is missing, and Chara seems to be gone as well. After inter grating into society (after some years) things are really looking up for monsters. Toriel is a high school teacher, Alphys is a leading scientist and is helping make major advances in technology, papyrus and undyne took a similar path both becoming police officers. Asgore is working as ambassador for monsters (frisk is to young for that job). Mettaton got himself a career in acting and singing.

As for sans he just works a simple job at the public library, but... He has quite the interesting night job as well. Follow sans's journey for the true meaning of justice, come to terms with his past. As well as hide his double life from friends and family and have an encounter that could change his way of life forever. (I don't want to give too many spoilers in the summary :p)