The character known as Mysterious Witch (or Mujer misteriosa in Spanish-language contexts) appears across multiple narrative segments within the series. She operates as a manipulative orchestrator of events, exploiting human desires and psychological vulnerabilities. Her interventions target individuals during moments of personal crisis or uncertainty, presenting cryptic propositions that fulfill hidden urges, often yielding destructive outcomes.

A recurring tactic involves her asking targets if they can "see their backs"—a phrase triggering their descent into scenarios where fantasy and reality blur. This manipulation ensnares victims in their deepest fantasies or fears. For example, she approaches a conflicted college student outside a massage parlor, provoking a confrontation with a doppelgänger masseuse that awakens the student's submerged desires.

Her methods vary but consistently warp reality. She manifests as a fortune teller delivering ignored warnings, culminating in a victim’s abduction and public humiliation. Elsewhere, she enables a voyeur’s obsession with a nurse to manifest a supernatural entity; this entity merges with him during a hospital stay, resulting in an assault on the fixation target. She also facilitates supernatural control through a fantasy card game, allowing a man to pull victims into an alternate dimension depicted on the cards.

Additionally, she exploits fractured familial relationships, enabling a stepmother’s seduction of her stepson. This interaction leads to a role reversal where the stepson becomes dominant, highlighting her corruption of interpersonal dynamics. While her objectives remain undefined, her actions consistently culminate in the psychological or physical enslavement of individuals within her realm.