Religious conversion represents one of psychology's most compelling phenomena, yet comprehensive psychological analysis of dramatic transformations remains limited, particularly regarding perpetrator trauma and multi-theoretical integration. This qualitative single case comparative study examined the psychological transformation of Saul of Tarsus from violent persecutor of early Christians to the Apostle Paul, addressing a critical gap in understanding personality change, religious conversion, and trauma-informed transformation processes. The purpose was to systematically analyze Saul's pre-conversion psychological characteristics, Damascus Road conversion experience, post-conversion functioning, and mechanisms accounting for observed changes. The study integrated five theoretical frameworks—trauma theory and post-traumatic growth, conversion psychology, personality psychology, attachment theory, and the biopsychosocial model—employing six-phase thematic analysis on three comprehensive psychological assessment documents totaling over 1,100 pages. Analysis yielded 11 major themes with 41 sub-themes organized across three temporal periods. Pre-conversion findings revealed rigid authoritarian personality structure with Obsessive-Compulsive Personality Disorder features, systematic violent persecution with antisocial behavioral patterns, extreme religious zealotry with identity fusion to Pharisaic Judaism, and absolute moral certainty with cognitive rigidity. The Damascus Road experience functioned as a traumatic transformation event involving sudden worldview collapse, physical trauma (temporary blindness), acute identity crisis, and overwhelming cognitive dissonance that shattered fundamental assumptions about self and meaning. Post-conversion findings documented robust post-traumatic growth across all five domains (empathy, meaning-making, spiritual development, personal strength, life appreciation) coexisting with residual trauma symptoms including PTSD-like features and chronic moral injury. Notably, personality continuity amid change revealed core traits (intensity, determination, perfectionism) persisted but were redirected toward apostolic mission rather than eliminated, alongside attachment transformation from anxious-insecure to secure patterns. Major theoretical contributions include trauma-informed conversion psychology framework, perpetrator trauma and post-traumatic growth theory extension, and the trait redirection concept demonstrating personality characteristics can be channeled constructively rather than requiring elimination. Clinical implications address moral injury treatment, rehabilitation of violent offenders through identity transformation, and pastoral care for individuals navigating dramatic religious conversions involving both growth and psychological costs.