After transmigrating to another world, Marius Lynn awakens as a priest, the weakest and most mocked support class. But when he binds with a divine contract system, he defies everyone and forms contracts with three so-called failures: Quin Smith, a crippled campus belle; Ruby Trent, cursed by beast blood; and Yvette, a girl with a broken soul. As a rule-breaking "battle priest," Marius heals with both Holy Light and brute force. He restores the three girls, unlocks their S-rank talents, and forms a ruthless team feared by all. From crushing noble families and sweeping dungeons to conquering the Skyward Tower, Marius exposes the Holy Curia's pact with the Abyss and violently purifies the Abyssal power inside Saint Alice. In the final war across the far northern icefields, Marius leads his team to full awakening, slays Erebus, the Abyssal Demon God, and saves the world—becoming a legendary priest, protector, and unstoppable healer.