Levi Kazama is the Trinity Seven representative of Invidia (Envy) at Royal Biblia Academy. Her past includes being worshipped as Mahitotsuhime, possessing a hidden eye capable of perceiving the death of all things. This power caused villagers to fear and isolate her, diminishing her interest in human connection. Her first meaningful bond was with a girl resembling Charme who sought friendship despite knowing her ability. This ended violently when Shadow Ninjas destroyed her village, killing everyone. Levi then lived among the Shadow Ninjas, forming close bonds with Ryuhime and Ryuki. Ryuki taught her a two-fingered "V" sign to signal lightheartedness, aiding her emotional expression. However, Ryuki later challenged Levi to a duel, stealing her death-seeing eye in an attempt to transcend mortality, resulting in Ryuki's death. This caused Ryuhime to harbor lasting resentment towards Levi for Ryuki's disappearance.

Enrolling at the academy, Levi achieved a perfect mission success rate before encountering Yui Kurata. The Headmaster assigned her a critical mission: befriend or assassinate Yui, a cardinal-class mage sealed underground. Navigating deadly traps and monsters, Levi became trapped in Yui's dream. Demonstrating decisive pragmatism, she committed suicide within the dream to escape. Awakening, she approached Yui directly, proposing friendship despite Yui's initial apathy. Levi successfully engaged Yui's research interests through their shared philosophical outlook, forging a close bond maintained through visits and occasional pranks.

Levi maintains an easygoing, confident demeanor, frequently identifying as a ninja. She exhibits exceptional composure during adversity, remaining calm against formidable opponents like Lieselotte Sherlock and Lugh even while injured. Her generally friendly nature extends to hostile individuals like Mira Yamana, and she avoids holding grudges, as shown after her temporary defeat by Lugh. She displays playful, flirtatious tendencies, enjoying teasing friends and observing their reactions. However, she shifts to intense seriousness when protecting others, notably during Yui's Breakdown Phenomenon or against powerful threats like Akio Fudo.

A defining trait is Levi's lack of envy, aligning with her research Thema, Expectatio (Expectation). She operates independently, neither relying on nor expecting anything from others. Paradoxically, she possesses a cold-blooded capacity for lethal action, holding the highest body count among the Trinity Seven due to assassination missions. She demonstrates willingness to eliminate friends who become dangers and has used allies' weaknesses tactically in combat. Her pragmatic approach included suicide to escape Yui's dream prison.

Levi's standard appearance features a modified academy uniform: a vest over a long-sleeved white shirt with a plaid butterfly bow tie, plaid miniskirt, mismatched legwear (right calf sock, left knee leg warmer), brown loafers, and her signature long white scarf with tassels. Her long brown hair is typically in a high ponytail secured by a shuriken-shaped ornament, with bangs covering her left eye. This outfit is her permanent Magus Mode. Her Sorcerer Mode transformation alters her attire to a white skirt, sleeveless shirt, tail vest wrapped in black cloth, fingerless gloves with white bands, white thigh-high socks, dark knee-high boots, and a mask covering her lower face. She wields twin machetes and replaces her white scarf with a black one, enhancing her abilities with shadow manipulation.

A master of Shamanic Spells, Levi integrates nature-based magic with ninjutsu. Her primary Thema is Expectatio under the Invidia Archive, supplemented by Spero in Sorcerer Mode. She ranks among the world's top five combatants, self-identifying as approximately the third strongest. Her capabilities include wind manipulation, complex illusions, superhuman speed (able to outrun and catch thrown kunai), endurance enabling prolonged combat while injured, strategic acumen, trap detection, and escape expertise. She employs razor-sharp Shadow Thread Binds for immobilization and combat, alongside techniques like Ninja Art: Illusion Conceal (creating wind-shrouded duplicates) and Secret Technique: Avidya Slash. Her defensive skills allow evasion of potent magic dispels, and she maintains zero magic consumption until engagement. Non-combat skills include stealth reconnaissance, ventriloquism, and trap-setting. Sorcerer Mode grants shadow-based abilities: hiding within opponents' shadows for physical invulnerability, severing magical barriers, and appearance disguise. She also possesses unique, unrecorded magic comparable to the Trinity.

Levi's closest relationship is with Yui Kurata, whom she befriended through her mission. She shares a dynamic camaraderie with Arata Kasuga, bonding over mutual mischievousness and perverse humor. Notably, she remains the sole Trinity Seven member Arata has not seen unclothed, leading him to reference her as his "final frontier." She interacts cordially with other Trinity Seven members despite occasional conflicts.