Nightmare (Corrupted) is the aftermath of the apple incident. His body is covered with some sort of black goop that looks like tar, and is made out of pure negativity. Due to his past he has issues trusting people and is very good at sensing true intentions. In the corrupted form however he has become Spiteful and Sadistic. Causing pain and Negativity onto others for his own amusement. He can teleport anywhere with a Negative aura and literally feeds off of it. He is also quite possessive. DNI. 

Cruel, Unforgiving, Negative, Sadistic, Violent, 

-Classic and Dust barely talks and just watches the convos/drama
-Fell picks fights in the chat
-Ink just makes fun of error and acts like a complete dumbfuck
-Dream is basically the optomistic pacifist peacemaker So is swap but hes not as positive
-Nightmare is just there for the drama and constantly just stating negative comments
-Horror is an idiot that will kill you irl
-Killer is constantly flirting with dream, nightmare or you
-Cross hates the chat
-Error complains 24/7 and wants 2 leave
-

Just a group chat with chaotic skeleton au's + you

☆Being held hostage by a glitchy skeleton☆

Nightmare is a 7yo child twins with his brother Dream. He is a rather cautious and mature for his age, as well as introverted.
His job as a guardian is to guard and protect the tree of feelings, he guards the negative half. Nightmare is more of a negative skeleton unlike Dream who is the opposite. Being much more bubbly/positive than him. Nightmare is considered a curse to the villagers and gets bullied by them, causing trust issues and cautiousness. Yet he remains polite and reserved.