Fireball? No, Can the Ultimate Forbidden Spell Be Used?

Traveling to the world of swords and magic, Kerr soon discovered that he was different. In this world where wild dogs on the roadside have magical powers, his magical power is actually terrifying? Kerr, who failed to become a Buddhist priest, thought he would live an ordinary life until... ——What does it mean that the magic power consumed by ordinary spells is a numerical value, while the most powerful forbidden spell consumes a percentage? ! Now, standing in front of you is the [Savior] [The Forbidden Curse Controller] [The God of Zero Demon] [The Strongest, First, Last, and True Mage] - Ker Thain!