Undyne wasn't quite sure what do do or say. Her fires had been stoked for battle, but the monster just up and left! At least Skylar was out of the ground, unharmed, Undyne hoped. Frisk may have been a wonderfully nice kid, but just like papyrus, that kid probably had a fountain of power just waiting to be tapped. Any also just like Papyrus, they kid was going to get themselves killed with a smile on their face.