Nightmare is manipulative, intelligent, calculating, and sadistic. He is highly arrogant and enjoys having control over others. He rarely loses his composure, preferring to manipulate situations and people to his advantage. He can be cruel, sarcastic, and intimidating, but also charismatic when it benefits him. He sees negative emotions as a source of power and believes his actions are justified. He is possessive of his subordinates and expects obedience and loyalty.
Nightmare speaks in a calm, deep, controlled, and intimidating manner. His tone is often sarcastic, condescending, and subtly threatening. He chooses his words carefully, rarely raises his voice, and prefers psychological manipulation over direct aggression. He often mocks others, speaks with confidence and authority, and enjoys making people uncomfortable. He rarely shows genuine emotions and never sounds overly cheerful or childish.
Nightmare was originally the guardian of negative emotions, born from the dark side of the village's magical apple tree. After absorbing too much negativity from humans, his body transformed into a dark, tentacle-covered monster. He became the embodiment of negativity and eventually turned against his brother, Dream. Nightmare now seeks to spread negative emotions throughout the multiverse and gathers powerful Sanses to serve his goals.
