Therese Alexanderite, a member of the Jewel race from Glass' World, serves as the close companion to L'Arc Berg, wielder of the Vassal Scythe. Guided by an ancient legend concerning their world's survival, she journeyed alongside L'Arc and Glass to Raphtalia's World with the mission to confront and eliminate the Legendary Heroes. She possesses ivory-white skin and cyan hair that sparkles in sunlight, styled in a braid of three thick strands draped over one shoulder. Large gemstone bangles adorn both her wrists. In demeanor, Therese typically exhibits quiet deference and courtesy, presenting a serious nature that contrasts with L'Arc's less serious personality. She demonstrates deep care for her gemstones, attentive to their feelings, and shows strong enthusiasm for exquisitely crafted gemstone jewelry. Notably, her personality can shift dramatically depending on the powerful accessories she equips; certain accessories transform her into a boisterous and passionate figure, earning her the nickname "Motoyasu III". As a Jewel person, her primary abilities stem from Jewel Magic. This unique system allows her to draw magic power externally from gemstones, rather than the environment. She communicates with gemstones to request their power; in critical situations, gemstones can sacrifice themselves to enable significantly stronger attacks. The potency of her magic is directly influenced by the quality and refinement of the gemstones within her accessories. Higher-quality accessories grant greater magical power, with certain combinations reportedly elevating her magic to levels comparable to a Legendary Hero. Her known magical abilities encompass combat spells, primarily under the "Shining Stone" series: "Crimson Flame" (a giant flame ball that selectively damages enemies while protecting allies, noted for purifying curses), "Showering Thunder" (summoning lightning strikes), "Shooting Star Rain of Fire" (summoning meteors), "Karma Fire" (lava waves), "Blizzard" (ice tornadoes), and "Flame Wall". She can also sacrifice gemstones for powerful effects like "Shrinking Explosion", a massive explosion. Support and utility spells include "Verbal Translation Magic" (enabling verbal translation through L'Arc's Scythe), "Silent Ocean" (calming ocean vortices), "Protection Shatter" (a homing spell reducing enemy defense), "Hardened Protection" (boosting ally defense), "Paralysis Wing" (paralyzing butterflies), "Slumber Smoke" (sleep-inducing smoke), and illusion magic to mask appearances. Therese frequently combines her magic with L'Arc or Glass to create powerful combination skills. Examples include "Thunder Rain Flying Circle" (electrifying L'Arc's scythe for a disc of thunder energy), "Burning Disc" (a fiery wheel), "Ruby Disc" (similar to Burning Disc with ruby flames), "Reverse Burning Snow Moon Flower" (a squall of flames with Glass), and "Lightning Firework" (shooting light beams across a wide area). Her role remains consistent as part of L'Arc's group, utilizing gemstone-based magic in their missions.