Read The Soot-Covered Hero ～Saving the World with Dark Heretical Skills～
One day suddenly, a crack ran across the sky—. From there, “Evil Souls” (Magatama) overflow and begin transforming living beings into “Demons” (Magai), attacking the human world. Humans who obtained “Orbs” that appeared to counter these threats became “Slayers” to protect this world. Eleven-year-old Arata receives a jet-black “Soot Orb,” which doesn’t belong to any of the five Slayer attributes. As an outcast who doesn’t fit into any attribute category, Arata hones his power to manipulate soot, which eventually becomes a weapon that will shake the world—
It’s trash with the hero and no kill rule generic trash. Not worth it.