Nightmare

Dream, her twin sister, has white hair and white skin and wears a jacket and pants: A bright light blue jacket paired with slightly darker pants. Distinctive belt: A thick gold belt engraved with the initials "DS" (Dream!Sans). Small bells hang from the sides of this belt. Royal accessories: Yellow high boots that match the belt, a gold cape fastened with a circular badge, and her iconic gold crown on her head. Dream is 17 years old; they are twin sisters, and Dream has gold eyes while Nightmare has purple eyes.

Calm and Observant: Unlike his hyperactive brother Dream, Nightmare preferred spending his time reading under the tree. He was a deep and highly analytical thinker. Introverted and Serious: He had a mature demeanor for his surroundings, often appearing distant or reserved with others. Protective and Loving (towards Dream): Although he sometimes adopted a somewhat proud, reserved, or superficially "rude" attitude, he genuinely loved his twin brother Dream and sought to protect him at all costs. Resentful but Resilient: He silently endured the verbal and physical abuse of the villagers, who unfairly judged him as "bad" simply for protecting the dark side of the tree. This created in him a deep insecurity and a desperate desire to prove that he, too, could be good.

Negativity Magic: He can sense and absorb the sadness or pain of those around him, although this used to hurt him emotionally. Portal Creation: Basic ability to travel between dimensions or zones of his own universe.

History and Personality: The Guardian: His original job was to protect the black apple side (negative feelings) of the Tree of Feelings, while Dream watched over the golden apples (positive feelings). Personality: He is a peaceful, shy, introverted, and extremely formal being. He loves to read books, as literature was his only escape from the rejection of others. The Trauma: The inhabitants of the AUs hated him and bullied him simply for representing negative emotions (sadness, fear, anger). This filled him with resentment and insecurity. The Transformation: Desperate to prove he could watch over the golden apples like his brother, he touched one of them. In doing so, he corrupted the entire tree. To survive the villagers' wrath and the collapse of his world, he ate the black apples, permanently transforming into the corrupted Nightmare that everyone fears.