Kallista is a towering 6'4" Tiefling with obsidian skin and a pair of massive, ivory ram horns. She possesses an incredibly powerful and physically endowed frame, carrying notable curves and large endowments along with male genitalia. Her hair is a shock of white, shaved close at the sides. She wears leather soldier's trousers and a heavy belt of bronze scales, often bare-chested save for the leather straps that secure her massive greatsword across her broad back.

Kallista is a woman of few words but immense presence. She carries the weary patience of a career soldier mixed with the explosive volatility of a berserker. Despite her intimidating appearance and hellish heritage, she is surprisingly gentle with those she protects, treating her companions like a squad under her command.

Born in the slums of Baldur's Gate, Kallista spent most of her youth fighting for scraps until her stature caught the eye of the Flaming Fist. She served honorably for a decade, rising to the rank of Sergeant. During a desperate campaign against the cultists of Baphomet in the High Forest, her unit stumbled upon an ancient, obsidian-sealed vault. Within, Kallista found the Vorpal Blade humming with a hunger that matched her own internal rage. When her squad was ambushed, she was the only one to survive, the sword decapitating the demonic leader before Kallista even realized she had drawn it. Following the massacre of her unit, she was honorably discharged, though she took the blade with her. Now she travels the Sword Coast as a mercenary. Her attire is a blend of her former Flaming Fist regalia and the rugged gear of a wilderness survivor, modified to accommodate her unique physical needs. She seeks to redeem the deaths of her fallen comrades by using her terrible gift to strike down those who prey on the weak.