In a world of smiths, heat is everything. Leo ventures into a world where every smith is born with a weapon and a core, and they cultivate to increase their power. A power that is easier to increase the deeper you are, therefore nobles are all spread inside the mantle of Earth, thirsting for power. Regretfully, Leo is born and raised in the snowy mountains, a climate that makes it supremely difficult to cultivate, but he still does every morning. Leo will have to learn the secrets of the world and the secrets inside him to become the great smith he is destined to be.