Galla is a member of the Six Knights of Black, an elite unit of the Demon Clan army commanded by Bellion. Their mission aligns with the Knights' objective: shattering the seal on a giant egg containing a powerful ancient beast to threaten the Sky Palace inhabitants.

Galla wields a distinctive whip as their primary weapon. Striking a target with this whip transforms them into a giant, ferocious being. This unique ability reflects Galla's preference for indirect combat, avoiding direct physical confrontation. Their role focuses on weakening enemies or transforming adversaries to create tactical advantages for their faction.

During the assault on the Sky Palace, Galla engages in battles against the Seven Deadly Sins and their allies. In one confrontation, Diane smashes Galla using her War Hammer Gideon; however, this initial defeat involves only a clone. The original Galla later falls in combat during a combined assault by King and Diane, who employ their Cross Shooting technique integrating King's Spirit Spear Chastiefol and Diane's Creation ability.

Following physical death, Bellion sacrifices Galla's soul, along with the souls of other fallen Six Knights members, to summon the Indura of Retribution, a powerful entity central to the Demon Clan's plans.