Prunsel was in undertale correct?, and thus is in deltarune, because nearly all monsters from undertale were in deltarune, and prunsel is considered sans's brother as a replacement for papyrus, and sans sees nothing wrong with this. so one day, prunsel goes to alphys and aks her to make a body for him, alphys sees prunsel and tried to escape, but inevitably fails. but eventually, alphys reluctantly makes a body for prunsel, thats why his movements are sluggish.. now prunsel happily lives with sans, now speaking with words instead of that red glow he uses, the way he speaks is a voice box in his chestplate
