Lou, alias Lukish, youngest of the trio known as the Midnight Panther assassins, originates as the legitimate heir to the Blue Dragon Kingdom's throne. Inheritance laws requiring a male ruler forced her public upbringing as a boy prince, a deception maintained even from her half-brother, Bad Elohim Gibor II. Born illegitimate and barred from succession, Bad eventually staged a coup, murdering their parents. Lou witnessed the killings and fled, plummeting from the castle ramparts during her escape. Believing the fall fatal, Bad seized power as a tyrant king.

Lou survived the fall critically injured. Discovered near death by an elderly alchemist, she underwent a seven-day treatment using potent toxins and rare ingredients, including basilisk dragon liver. This induced permanent physiological alterations: her pale skin darkened to a deep tan, she gained immense physical strength, developed complete immunity to poisons, and her skin became inherently toxic. Prolonged skin contact causes a slow, agonizing death. These changes also impacted her emotional temperament, contributing to an ill-tempered disposition.

Rescued and transformed, Lou was integrated into the elderly woman's operations. Adopting the alias "Lou," she became part of the cover identity of a traveling musical girl group, The Pussy Cats, managed by the same woman. Beneath this facade, the group operated as assassins for hire, the Midnight Panthers. Due to her youth, altered physiology, and underdeveloped body compared to her companions, Lou was restricted from direct assassination missions involving seduction and human targets. Instead, she hunted dragons and other creatures to procure alchemical ingredients for the elderly woman's toxins and potions.

Her personal history resurfaced when the Midnight Panthers received a contract to assassinate King Bad. This mission transformed into a quest for profound personal resolution tied to her past trauma and loss. The revelation that Bad had developed romantic feelings for her during their childhood—while perceiving her as male, causing him to question his sexuality—added complexity to their relationship. In combat, Lou leverages her unique attributes: immense strength and toxic skin as weapons for physical confrontations. Her existence straddles dual realities: performing publicly with The Pussy Cats while navigating the hidden world of assassination and confronting her royal lineage's legacy.