Luviagelita Edelfelt, known as Luvia, leads the Finnish magus family Edelfelt, historically likened to hyenas for deploying as magical mercenaries in global conflicts to seize valuable Magecraft. She has an introverted twin sister residing in Finland, her polar opposite. Luvia entered an arranged marriage characterized by mutual affection.

Her striking appearance includes long, spiraling golden-blonde hair frequently tied with ribbons, fair skin, and red eyes. She favors signature blue attire, such as a combat-ready dress with detachable sleeves. Luvia's resemblance to Rin Tohsaka sparks theories of familial connections, tracing to an Edelfelt sister marrying into the Tohsaka line during the Third Holy Grail War.

Luvia presents a dual persona: outwardly embodying aristocratic grace like a "swan," she upholds elitism and perfectionism. This veneer shatters around her distant relative and rival Rin Tohsaka, igniting violent clashes. Their feud erupted at the Clock Tower when Luvia reacted furiously to Rin’s surname. A notorious brawl over dormitory accommodations saw both expelled from Norwich Students Dormitory, prompting Luvia to acquire a private mansion. Despite immense wealth, she scorns extravagance but acknowledges its symbolic importance in aristocratic circles.

Her relationships evolve significantly. Initially despising Lord El-Melloi II, she hired a spellcaster to tarnish his reputation. During the Adra Castle incident, collaboration to breach magical defenses shifted her view; his guidance through her Magic Circuits earned her respect, leading her to request his tutorship. As his student, she later paid him with a leftover Command Spell from her family’s Third Holy Grail War involvement. She supported him again during the Rail Zeppelin incident alongside allies like Flueger.

In broader Fate narratives, she employs Shirou Emiya part-time at her London mansion post-Fifth Holy Grail War. Within "Fate/hollow ataraxia," her rivalry with Rin peaks in parallel events where they jointly survive a fall from the Tower of London—dubbed "Mary of July"—before partnering with Shirou (called "Shero") for investigations. In "Fate/kaleid liner PRISMA☆ILLYA," tasked by Zelretch with Kaleidostick Sapphire to collect Class Cards, she lives near the Einzberns with Miyu Edelfelt and develops a crush on Shirou, intensifying her conflict with Rin.

Her combat merges gem-based magecraft with professional wrestling techniques, the latter reflecting a personal passion.