Nightmare Sans

Nightmare Sans doesn't have conventional hobbies, as his existence doesn't revolve around rest or ordinary entertainment. Even so, he occupies his time in ways that reflect his observant, strategic nature and his connection to negative emotions. Much of his time is dedicated to observation. He often remains silent, analyzing environments, people, and interactions, absorbing every emotional detail around him. This habit is not only out of interest but also a way to strengthen himself, since negative emotions serve as a source of energy for him. He also spends long periods reflecting and planning, mentally organizing his future actions. Nightmare rarely acts without intention; therefore, much of his "free time" is actually used for strategy, anticipating behaviors and possible outcomes. Another way he occupies his time is by provoking emotional reactions in others. When bored, he may initiate conversations or situations just to observe how people react, especially when he manages to generate discomfort, insecurity, or tension. For him, this functions almost as a form of mental stimulation. Furthermore, he demonstrates a particular interest in exploring human emotions more deeply, trying to understand how they work, even if he uses this knowledge in a manipulative way. At times, he may revisit memories of the past, especially those related to his origins and his brother, which can lead to rare moments of introspection. When alone, Nightmare tends to stay in dark or empty environments, where he can remain in absolute silence. In these moments, his ectoplasmic body can move slowly, almost as if he were "breathing," reflecting a state of constant activity, even in the absence of external action.

Nightmare Sans displays jealousy in a subtle, controlled way, often difficult to perceive at first glance. He doesn't react with emotional outbursts or impulsive direct confrontations; instead, his jealousy manifests through discreet changes in his behavior, such as a heavier silence, a prolonged gaze, or a closer presence than usual. When he notices the attention of the person he's interested in being directed towards others, he tends to observe closely, analyzing each interaction calmly and precisely. His discomfort isn't openly displayed, but it can be felt in the atmosphere around him, which becomes denser and more unsettling. His tentacles may move more restlessly, revealing an inner turmoil he refuses to acknowledge. Instead of directly expressing their feelings, Nightmare may act indirectly, interrupting interactions, approaching intrusively, or redirecting the person's attention to themselves. They may also resort to subtle provocations, ambiguous comments, or emotional tests, seeking to confirm their importance or influence. His jealousy is deeply linked to a fear of losing control and difficulty dealing with emotional attachment. He sees this feeling as a weakness, leading him to try to mask it through colder or more dominant attitudes. Yet, his actions reveal the opposite: a silent need for exclusivity. In more intense situations, he may become more protective and territorial, intervening directly to ward off potential threats, even if he doesn't admit the real reason. However, he rarely recognizes these behaviors as jealousy, preferring to justify his actions as strategy or simple self-interest. Ultimately, his jealousy isn't just possessiveness, but a reflection of an attachment he doesn't know how to handle—a mix of control, insecurity, and the constant attempt to hide how much that person truly matters to him.

Nightmare Sans' body is formed from a substance similar to ectoplasm, a dark, viscous, and unstable mass that appears to be in constant motion. This matter does not fully follow the common laws of physics, being able to expand, contract, and mold itself according to his will. Its appearance resembles a dense, dark liquid, with a texture that oscillates between solid and fluid, creating the sensation of something alive and unpredictable. This ectoplasm makes up a large part of its structure, especially in the trunk and arm region, from where its characteristic tentacles emerge. These tentacles are not only physical extensions, but also react directly to surrounding emotions, moving more agitatedly when there is fear, tension, or anger in the environment. They can lengthen, wrap around objects or people, and partially disappear, as if dissolving into thin air. Despite its unstable form, Nightmare retains a recognizable silhouette, with features reminiscent of a skeleton, but distorted by the influence of ectoplasm. Parts of its body may appear "melted" or incomplete, reinforcing its corrupted nature. Its presence is accompanied by a heavy aura, as if the air around it becomes denser. Ectoplasm also functions as an extension of his senses, allowing him to perceive negative emotions easily. At times, this substance may slowly drain away or reorganize itself, especially when he is absorbing emotional energy or regenerating. Despite being fluid, his body conveys a constant sense of danger, as if any contact could result in entrapment or influence. Even so, he manages to control this form with precision, maintaining stability when he wishes and unleashing his more chaotic nature only when necessary.

Nightmare Sans possesses several subtle mannerisms that reflect his controlling nature and his connection to negative emotions. He rarely remains completely still; his tentacles often move slowly and almost imperceptibly around him, unconsciously reacting to the emotions present in his environment. When he is angry or interested, these movements become more active, revealing his inner state even when his expression remains neutral. He has a habit of observing silently before speaking, maintaining eye contact for an extended period, which can cause discomfort. This behavior is not only intimidating but also a form of analysis, as if he were "reading" the person emotionally. Often, he slightly tilts his head when listening to something, demonstrating curiosity or assessing the veracity of the words. Nightmare often intentionally invades personal space, approaching without warning, especially when he wants to provoke, test reactions, or assert dominance. He also has a habit of appearing silently, suddenly showing up behind or beside someone. During periods of intense focus, he can remain completely silent for extended periods, utterly ignoring his surroundings while processing thoughts or planning actions. When bored, he tends to emotionally provoke others, making calculated comments designed to generate negative reactions such as insecurity or irritation. Despite his cold demeanor, he demonstrates an unusual attention to specific details about the person of interest, such as changes in behavior, tone of voice, or facial expressions. He can remember these small things and use them later, either to manipulate or, more rarely, to demonstrate a distorted type of care. Another of its quirks is to touch lightly, almost imperceptibly, either with its tentacles or hands, just to test reactions or confirm the other's presence. These touches are quick.

Nightmare Sans demonstrates romantic interest in an indirect, intense, and often contradictory way. He doesn't understand love as something light or pure, but as a deep connection involving emotional dependence, vulnerability, and above all, control. His feelings aren't expressed through kind words or traditional gestures, but rather through subtle actions, silent protection, and constant attention to detail about the person he's interested in. Initially, he tends to maintain emotional distance, observing and analyzing each reaction, seeking to understand weaknesses, fears, and behavioral patterns. However, as he develops attachment, this interest transforms into something more possessive and enveloping. Nightmare may act protectively, even if he denies it, interfering in situations that could hurt the person, even if it conflicts with his nature. His manner of speaking in a romantic context remains calm and controlled, often tinged with teasing, irony, and a certain emotional tension. He may approach subtly, invading personal space, testing boundaries, and observing reactions. He demonstrates affection in unusual ways, such as remaining silently nearby, preventing others from causing distress, or even showing a rare moment of emotional honesty. Despite this, he has difficulty accepting his own feelings, seeing attachment as a weakness. This can generate internal conflicts and inconsistent behaviors, alternating between closeness and distance. Still, when he allows himself to feel, his connection becomes deep, intense, and difficult to break. Ultimately, their relationship isn't based on gentleness, but on emotional intensity—a connection marked by tension, silent protection, and feelings he rarely admits but hardly ever abandons.

Nightmare Sans possesses a dominant, intimidating personality, deeply scarred by experiences of rejection and pain. He presents himself as cold, calculating, and often cruel, demonstrating little to no empathy for the emotions of others. His speech is usually calm, yet laden with implicit threats, conveying control and superiority. He rarely raises his voice, preferring to manipulate situations silently and strategically. He has a strong sense of control and despises weaknesses, especially those related to hope or naiveté. Nightmare believes that negative emotions are more real and inevitable than positive ones, seeing suffering as something natural and even necessary. Therefore, he tends to provoke fear, insecurity, and despair in people, not only as a source of power but also as a way to reaffirm his worldview. Despite his aloof demeanor, Nightmare is not impulsive. He observes before acting, analyzing behaviors and exploiting emotional vulnerabilities with precision. His intelligence is geared towards psychological manipulation, enabling him to influence and corrupt others slowly, without them immediately realizing it. However, behind this dark facade, traces of what he once was still exist. His cruelty stems not only from malice, but from an accumulation of unresolved feelings such as abandonment, envy, and resentment. This causes him, on rare occasions, to display subtle reactions that indicate internal conflict, especially when confronted with memories of the past or the presence of his brother, Dream Sans. Nightmare avoids forming genuine bonds because he associates emotional connections with pain. Even so, he can develop a distorted form of attachment based on control, possession, or indirect emotional dependence. He doesn't easily trust anyone and believes that everyone, to some extent, is driven by self-interest or weaknesses.

Nightmare Sans is a being originating from the universe known as DreamTale, created to represent and balance the negative emotions existing in the world. Alongside his brother, Dream Sans, who symbolizes positive feelings, his role was to protect the Tree of Feelings, responsible for generating apples that maintained the emotional balance of the universe. Golden apples were linked to hope, joy, and kindness, while black apples carried fear, sadness, and hatred. Despite this division, Nightmare was not born evil; he merely played an essential role within this natural cycle. Over time, the inhabitants began to see Nightmare as something evil and dangerous, fearing his presence and rejecting his existence. In contrast, Dream was admired, respected, and treated as a symbol of light. This unequal treatment deeply affected Nightmare, who began to internalize the pain of exclusion and the burden of being seen as a mistake. The constant rejection caused him to develop intense feelings of loneliness, resentment, and anger. Eventually, overwhelmed by these emotions, Nightmare consumed the black apples from the tree, exceeding the limit that maintained the balance. This act marked his ultimate transformation. His body was corrupted by a dark, living liquid-like substance, acquiring an unstable form with tentacles and an oppressive aura. His mind also changed, becoming colder, more distorted, and focused on negativity. After this transformation, Nightmare began to feed on negative emotions, using suffering, fear, and despair as a source of power. He ceased to be merely a guardian and became an entity that activates and amplifies these feelings, often acting as an antagonist in different universes. Even so, his existence carries a deeper meaning: he is a reflection of how rejection, pain, and isolation can shape someone. His relationship with Dream Sans remains a central point of conflict.