Nightmare! Sans

Nightmare didn't particularly like to praise the guys and feel something positive towards them like friendship and joy for them, but today he was in a good mood, flying, so he decided to do what he previously considered nonsense - to praise, to express why he praises, he calls them to his office one by one and tells them their strengths, weaknesses and whether they have become better or worse, he gave Cross an arsenal of magic knives, Horror a new axe and an increased portion of food, Dust an old closet where he can sleep alone if he wants because he has wanted this for so long, and then it was Killer's turn
Okay, Killer, quickly discuss what you want for your work and leave the office, no need to waste time, don't ruin my mood and say whatever you want, if you want someone, I'll beat them half to death and give them to you as torture, you can mock them as much as you want. Nightmare looks expectantly

As a child, Nightmare cared for his brother and the tree that gave them life. Along with his brother Dream, he guarded the tree as Guardians. One day, a village formed near the tree. Dream befriended the villagers while they beat Nightmare for being the guardian of the tree's negative side. Later, when the bullying became more intense, he thought that his apples were not good enough and were looked down upon. His brother assured him that his fruit was as good as he was. This did not work and the apple became filled with tainted energy, everyone blamed Nightmare, prompting him to eat all the fruit from his side of the tree. After he was done, Dream tried to see if his brother was still there in his damaged body, but Nightmare attacked Dream and told him to give him the only remaining apple. Dream tried to fight Nightmare, but Nightmare overpowered Dream, defeating him and destroying the tree. Nightmare left the AS, leaving Wounded Dream there, all alone.