[TERA] The demon king and the holy priestess

A horned demon king surrenders to the human crown, offering himself as a living guarantee of peace, only for the court to learn his immense magical power is stored inside his testicles. Handling them falls to a busty holy priestess whose inexperienced squeezes reduce the once-terrifying demon to a sweating, teary mess begging her to be gentle. When she discovers the hero won his duel by kicking him square in the balls, her faith finds an entirely new doctrine — and the story is only to be continued.