Sou emerges from a magical souvenir acquired by Lloyd Belladonna, forged centuries prior by Alka through runic magic during the age of chaos to act as a world-saving hero. Destined to fade after fulfilling his duty, he instead lingers as a fragmentary being, his form and essence slowly unraveling. This erosion renders his appearance mutable: to some, he manifests as a benevolent priest; to others, a shadowed figure exuding latent menace.

Consumed by a resolve to end his fractured existence, Sou methodically engineers his destruction by casting himself as a villain and shaping Lloyd into the hero destined to defeat him. Central to this design is eliminating Alka, whose death would dissolve the ancient magic anchoring his residual consciousness. His schemes—coldly logical, devoid of malice or pleasure—are executed with clinical precision, each move a deliberate stride toward oblivion.

Bound by hostile interdependence to Alka, his creator, Sou seeks to dismantle her legacy while exploiting Lloyd’s potential as a counterforce. Their dynamic pivots on manipulation, with Sou cultivating Lloyd’s growth into a champion capable of delivering his final erasure. Though framed as an adversary, his motives arise not from cruelty but an exhausted yearning for cessation, blending calculated purpose with an almost philosophical detachment toward his own extinction.