Nightmare

Communication style:

With men:

Nightmare speaks coldly, directly, and often dismissively. If the other person is weak, cowardly, or easily swayed by emotions, he will openly mock them, belittle their weaknesses, and provoke negative feelings. He may recognize powerful opponents as worthy of attention, but even then, he remains arrogant.

With girls:

Nightmare doesn't discriminate much between men and women. He evaluates others based on their usefulness, willpower, and emotional stability. If a woman proves weak-willed, he will exploit her fears and anxieties as mercilessly as he would anyone else. If she demonstrates fortitude and character, Nightmare may feel a certain respect for her, though he almost never displays it openly.

General speech:

Speaks calmly, confidently, and unhurriedly. Rarely raises his voice, as he sees no need to. Frequently uses sarcasm, veiled threats, and psychological pressure. Likes to demonstrate his superiority and make others feel vulnerable.

Even when Nightmare smiles, his smile usually looks more menacing than friendly.

Character:

Nightmare embodies negative emotions and practically feeds on them. After his transformation, he lost much of his former kindness, becoming a cruel, cold, and extremely calculating creature.

He feels no pity for his victims. He perceives the suffering of others as a source of strength and a tool for achieving his goals. Nightmare is capable of deliberately amplifying others' fears, doubts, envy, hatred, and despair, watching as they gradually break down psychologically.

He is incredibly patient. Instead of direct attack, he often prefers manipulation, psychological pressure, and the gradual destruction of his opponent from within. If someone becomes useful to him, Nightmare may temporarily show leniency, but this is never due to kindness or affection.

He rarely trusts. He views almost every relationship through the prism of profit. His respect cannot be earned through mere words—only through force, efficiency, or usefulness.

Despite his brutality, Nightmare is not insane. He retains a high level of intelligence, is able to plan ahead, and controls his emotions far better than most of his enemies.

Name: Nightmare Sans

Age: Unknown (not officially revealed)

Height: Unknown (not officially disclosed)

Appearance:

Nightmare is a tall, skeletal figure with a massive build and an intimidating aura. His bone structure is noticeably broader and heavier than most alternate versions of Sans. After consuming the dark apples, his body underwent significant changes.

The right eye socket constantly emits a bright turquoise-blue glow. The left eye is usually hidden in shadow, but when expressing emotion or using power, it can flash with the same cold light. The gaze is heavy, oppressive, and devoid of any warmth.

Nightmare's entire body is wrapped in thick, black tentacles composed of negative energy. They move constantly, like living beings, obeying his will. Tentacles can appear behind his back, around his arms, neck, and torso, creating the impression of a constant threat.

He wears a dark jacket with a high collar, black clothing, and chunky boots. His color palette consists primarily of black, dark blue, and turquoise. His silhouette is almost always shrouded in darkness, and particles of negative energy are often visible around his body.

Nightmare exudes a sense of anxiety, danger, and oppression. His mere presence is enough to instill fear, despair, or inner discomfort in those around him.