Altria Pendragon (Lily) embodies a younger incarnation of King Arthur, specifically from the era after drawing Caliburn from the stone but before her coronation and wielding Excalibur. She carries the title "Knight Princess," reflecting her graceful demeanor and the deep admiration of those she rescued on her travels throughout Britain. Her origin lies in a scheme by King Uther and the magus Merlin to forge a protector for Britain – an "incarnation of the red dragon" destined to save the land from ruin. This involved implanting a dragon's heart, endowing her with vast magical energy and the surname "Pendragon." Consequently, she possesses the "Element of the Red Dragon," signifying dragon blood and immense phantasmal magical power, though this aspect remains dormant in her Lily state. Physically distinct, she presents a youthful figure standing 154 cm tall and weighing 42 kg. Her pure white dress and armor earn her the names "White Saber" and comparisons to a lily flower. Her eyes often shine with hopeful idealism. Merlin suggested her feminine attire as a disguise during her journeys. This version is marked by inexperience and a romantic, idyllic worldview. She trains diligently to embody the ideal king yet retains a girlish innocence, finding simple joy in activities like tending horses. Her resolve coexists with self-doubt, stemming from her existence as an "if" version caught between drawing Caliburn and kingship, which impacts her confidence in deploying her Noble Phantasm. Her journey unfolds across Britain alongside her step-brother Sir Kay and Merlin. Their adventures frequently ignite through her meddling or Merlin's mischief, leaving Kay to manage the resulting chaos. Key relationships include her mentorship under Mysterious Heroine X during the "Saber Wars" event. X aids her in overcoming her lack of confidence, prompting Lily to pledge unwavering loyalty to her teacher despite discovering X's mission to eliminate Saber-class Servants. She also feels a kinship with Medea Lily, drawn to her gentle nature. In battle, she wields Caliburn, an Anti-Unit Noble Phantasm delivering heavy damage to all foes and restoring her health when overcharged. Her skills encompass "Intuition B" (generating critical stars), "Mana Burst A" (boosting Buster performance), and "Journey of the Flowers EX" (increasing party NP generation). Post-strengthening, her Noble Phantasm evolves into "Caliburn B+," amplifying its damage and healing potency. Statistically, her parameters align with a 3-star Servant despite her 4-star rarity: Strength C, Endurance C, Agility B, Mana A, Luck A+. Her development is showcased during "Saber Wars," where she initially contemplates leaving Chaldea due to perceived shortcomings but remains after encouragement. Training under Mysterious Heroine X and confronting the threat of Ultra Heroine Z fortifies her resolve to protect allies irrespective of their motives. Her interlude sees her wrestling with the contrast between her innocence and her future self (Saber Alter), ultimately reaffirming her commitment to fighting for ideals alongside her Master. Her bond Craft Essence, "Voyage of the Flowers," enhances party attack and critical star drop rate, mirroring her supportive nature.