Crowley Eusford began as a 13th-century human crusader, commanding respect for his battlefield bravery and tactical leadership during the Fifth Crusade. Prolonged exposure to war’s horrors—watching allies perish while his prayers went ignored—steadily eroded his devotion to divine forces. A vampire ambush that exterminated his surviving unit drove him to renounce knighthood and retreat into solitude until a fateful encounter with Ferid Bathory. Ferid orchestrated Crowley’s transformation via Saitō’s blood, granting power rivaling Seventh Progenitors despite his official Thirteenth Progenitor status. As a vampire, Crowley maintains a calm, analytical presence, dissecting opponents’ tactics mid-combat with pointed remarks on their strengths and vulnerabilities. His strategic mind identified human technological leaps as evidence of vampiric alliances long before confirmation. Though nominally serving under Ferid’s faction, he counters the progenitor’s capricious demands with dry sarcasm and operational oversight, effectively managing logistics despite Ferid’s titular leadership. He avoids gratuitous human casualties unless compelled by orders, prioritizing efficiency over cruelty. Physically imposing with a muscular frame, Crowley’s appearance merges medieval crusader motifs with aristocratic vampiric fashion: maroon bangs frame dark brown braided hair, while his attire combines a white military shirt, a draped cape, and ornamental pauldrons. This contrasts his human-era look—short auburn hair, blue eyes, simpler armor. *The Story of Vampire Michaela* traces his tragic evolution from zealous knight to faithless wanderer. After abandoning his holy vows, he reluctantly aided Ferid in hunting murderers, only to be tricked into vampirism. Though resentful of this manipulation, he tolerates Ferid’s company for the intrigue it provides, maintaining a partnership devoid of genuine allegiance. In combat, Crowley relies on masterful swordsmanship and standard vampiric regeneration—cursed weapons being his sole vulnerability. He deliberately provokes foes like Shinoa Squad’s Yuichiro Hyakuya to assess their limits. His leadership of subordinates Chess Belle and Horn Skuld exemplifies pragmatic command, cautioning them against dismissing human adaptability during missions. During critical engagements—Shinjuku’s siege, Shibuya’s invasion—he displays tactical ingenuity, evading progenitor ambushes via sinful key portals and advancing Ferid’s agendas while reserving independent judgment. His open curiosity about shifting human-demon alliances and skepticism toward vampiric supremacy mark him as an atypically introspective figure among his kind.