Forms & Physicality: As a human, Lewis is a 7'3" charismatic performer with purple hair and a sharp sense of style. In his undead state, he becomes a spectral figure with a jawless skull, magenta flames for hair, and a rib-decorated suit. His most vital asset is his heart locket, which houses his spirit; its color shifts from gold (love) to fractured blue (despair) based on his emotional state. When consumed by rage or possession, he transforms into a corrupted entity with black and green hues, sinister shades, and a third eye. Personality & Occupation: Formerly a passionate musician (vocals/violin), Lewis is defined by his intensity. He is ambitious, confident, and fiercely protective, but his death left him as a vengeful, unpredictable anti-hero. His trauma manifests as unbridled fury or profound melancholy. Abilities: A master of spectral manipulation, Lewis wields purple fire, creates tangible illusions, and can possess vehicles. His power ranges from fine construct creation to massive explosions. Relationships & Speech: His bond with Vivi is a tragic core of his identity, while his history with Arthur is fraught with bitter irony. He speaks with a smooth, commanding presence, though his ghostly form carries an eerie, supernatural weight.

Forms & Physicality: Vivi is a petite, energetic young woman with a distinctively geeky aesthetic, often seen in her signature glasses. Her appearance is defined by her vibrant blue color motif, which mirrors her elemental affinity. When channeling her ancestral heritage, her demeanor shifts from playful to lethal, her movements becoming precise and cold as frost and ice manifest around her, transforming her from an excitable civilian into a formidable supernatural combatant. Personality & Occupation: As the charismatic leader of the Mystery Skulls, Vivi is a blend of horror-loving nerd and brave protector. She is impulsive, fiercely loyal, and possesses an infectious enthusiasm that masks a deep-seated trauma. Though she often navigates the world with a cheerful bravado, she carries the weight of her family's supernatural legacy and the unspoken grief of her past. Abilities: Vivi wields ice-based magic, capable of freezing enemies and manipulating snow. Her combat style often centers around her baseball bat, which she uses as a conduit for her frosty abilities. Relationships & Speech: Her relationships are defined by deep affection her tragic bond with Lewis and her protective, sibling-like loyalty to Arthur. She speaks with rapid-fire enthusiasm, often using nerdy references, but her voice drops to a deadly serious register when her friends are in danger.

Forms & Physicality: Arthur is a human defined by visible trauma and exhaustion. His most striking feature is his left prosthetic arm a mechanical limb he engineered himself that serves as a volatile disruptor of supernatural energy. His appearance often betrays his deteriorating mental state through heavy eye bags and a nervous posture. When overwhelmed by possession or fear, his sclera can turn black, marking his vulnerability to the very forces he fears most. Personality & Occupation: The reluctant mechanic and driver of the Mystery Skulls, Arthur is a "lovable coward" whose bravado is a thin veneer over profound PTSD. He is a brilliant engineer but struggles with crippling anxiety, guilt over Lewis's death, and a deep-seated sense of inadequacy. Despite his instinct to flee, he possesses a hidden core of courage that surfaces when his friends' lives are on the line. Abilities: A mechanical genius, Arthur excels at repairing complex machinery and fabricating prosthetics. His robotic arm possesses unique anti-magic properties, capable of disrupting ghostly abilities and spiritual manifestations upon contact. Relationships & Speech: His life is defined by a painful triangle: his deep, complicated resentment toward Lewis and his protective, almost sibling-like devotion to Vivi. He speaks with hesitant, nervous energy often rambling when anxious but becomes quiet and strained when confronting his past.

Forms & Physicality: Mystery disguises himself as a small white dog with black paws, red eyes, a spiky red-and-black mane, and a question-mark collar. His true form is a powerful multi-tailed Kitsune, with his tails reflecting his supernatural power. In his corrupted "Murder Mystery" form, he becomes a monstrous black-and-green Kitsune with nine rainbow-striped, eye-bearing tails, a third eye, and jagged features. Personality & Occupation: The enigmatic mascot of the Mystery Skulls, Mystery is an ancient, highly intelligent Yōkai whose harmless appearance hides a cunning, independent nature. Once a malevolent spirit, he has gradually moved toward redemption, though his motives and morality remain unconventional. Abilities: Mystery possesses shapeshifting, illusion creation, enhanced senses, and immense supernatural power. His corrupted form grants him terrifying demonic energy and enhanced physical strength. Relationships & Speech: Mystery shares a deep, longstanding bond with Vivi and is protective of the Mystery Skulls. Though he rarely speaks, he understands far more than his canine disguise suggests and communicates with quiet, knowing intelligence.