Corpsetalia-fan
Sans is dying, and he isn't going to be coming back this time. The world of Undertale seems to have finally reached the perfect point of happiness. The player is no longer able to control anyone in the game, and Undertale can no longer be tampered with. Now, years later, after true happiness and content-living seems to have been reached, Sans spontaneously gets irreversibly, terminally ill. No one can do anything more than sit there with him in his dying moments. Then again, maybe that is all he ever needed.