Climax, Climax, Climax!

Kakouya is tormenting the daughter of a blacksmith, a girl named Rita. In her sex-induced daze, she sells the Dragon Fang to Azel. When equipped, it grants her the powerful Dragoon Armor, which allows her to defeat the Demon Lord Lasbos! But as he dies, he tells Azel that the seal on her body can't be removed.