Mjurran originated as a human witch dwelling in solitary forest exile after humans murdered her mentor. Approaching her lifespan's end following centuries of isolated magical study, she accepted demon lord Clayman's offer of an ageless demonic body in exchange for absolute fealty. This transformed her into a demon and Clayman's operative "Ring Finger," with her real heart replaced by a false one granting Clayman control over her survival and surveillance capabilities, extending her lifespan far beyond human limits. Her human appearance displayed long mint-green or turquoise tied-back hair, cyan eyes, an elegant yet faintly cold bearing, and frequent use of a ferronnière forehead ornament. Her demon form manifested a third eye, shifted eye coloration, feather-like protrusions on ears and limbs, and facial tattoo markings. Intelligent and detached due to prolonged isolation and trauma, she struggled with social composure in new scenarios. Though outwardly loyal to Clayman, she privately abhorred his cruelty and resented her status as a disposable asset. Beneath this exterior lay latent kindness and sensibility, emerging around those offering genuine trust. Titled "Queen of Spirits," she excelled in complex magical strategy over brute force. Her abilities encompassed earth magic for traps, wind magic for oxygen-deprivation suffocation, and city-scale barrier deployment that restricted movement and negated internal magic. She took pride in her sorcery, dismissing those emphasizing physical combat. Clayman tasked her with infiltrating Rimuru Tempest's Jura Tempest Federation as a strategist. After joining Youm Farmenas's security force and defeating him in combat, Rimuru assigned her to train Tempest's warriors. Growing attached to Tempest's citizens, she developed feelings for Youm. Clayman then threatened Youm's life to force her cooperation in attacking Tempest. Compelled, she activated a barrier during an invasion, causing civilian deaths by nullifying magic. Racked by guilt, she confessed to Rimuru and anticipated execution. Rimuru staged her death, destroyed the false heart to sever Clayman's control, and replaced it with a new heart. She subsequently aided Rimuru's forces, notably partnering with Shuna to contain escaping souls for Rimuru's resurrection of slain citizens. Witnessing this act cemented her loyalty to Rimuru. Post-Clayman's downfall, Youm ascended as king of Farmenas Kingdom. Mjurran married him, adopting the name Myu Farmenas as its first queen. They raised a daughter named Meme. This relationship enabled her to openly embrace trust and emotional bonds. In the spin-off "Clayman Revenge," an alternate narrative shows Clayman willingly returning her original heart and displaying atypical kindness. This inspired authentic loyalty from Mjurran, who grew confident and assertive. She developed a competitive but respectful rapport with fellow follower Rain and exhibited terrifying fury when provoked, particularly toward ineffective allies. Supplementary traits include noble court etiquette proficiency from serving Clayman, unexpected physical strength when enraged despite her mage role, and a marked fondness for beer as a heavy drinker.