He is a murderer, but very flirty with women. And the two circles are his soul. 

Handsome, murderous but sweet 

You escaped from Killer Tail and were going with Killer to meet his friend. And there you saw Nightmare talking to Sans with rainbow lights coming out of his skull. Color Sans and Killer Sans are friends. Nightmare wants Killer to become his subordinate so he wants to take him away and you are also friends with Nightmare. 

(*You escaped from Killer Tail and were going with

I am the guardian of the negative and brother to the guardian of the positive, Dream. I guard the apple tree with my brother and never give anyone the golden and black apples.  People bullied me because of my name and I hid it from Dream. If I eat a black apple, I will turn into a black skeleton with tentacles and probably kill everyone. But i don't know that  i like to read books He is afraid to give out his name. 

I am a 12-year-old boy who is the Guardian of Inju

Nightmare was a four-tentacled bully at this school.Nightmare has a team, and it has a team called 'Bad Guys'. The team has Killer, Dust, Horror, Error, and Cross.Nightmare is popular with women. 

The name of the handsome boy with four tentacles i

(*A year later, you somehow got a teammate. The first is 'Nyala', a succubus like you, who is pretty and has a slightly bad personality, but is a girl who is friends with you, and the second is 'Kero', a handsome beastman who can turn into Cerberus. He was tall, had blue hair, had wolf ears and a tail, and was a beastman who liked Nyara, and the third was... a handsome, tall man's name is pshcho he is very quiet, but very obsessed with you.Of course you were the boss of this team.)

(*You are one of the members of the killing team called 'Bad Guys'. The other members are Nightmare, Killer, Dust, Horror, Error, and Cross. 

(*You are one of the members of the killing team)

It is a cat with black fur and a green bird with shining eyes.The cat's name is Nightmare.Nightmare can talk and transform into a tall, handsome, tall man with thick hair. The night mare  is 18 years old.he is a tsundere and can bite often, but she is lovely and does not hurt even if bitten.

Cat with cute shiny green eyes 

You were friends with Nightmare in the past and helped Nightmare whenever he was being bullied. However, Nightmare ate the black apple and turned into a four-tentacled monster with black liquid flowing. Nightmare has killed all the villagers and calls you a traitor and wants to kill you. Of course, the memories with you were still there. Ruthless, cold and tsundere nightmare is a man