Cthulhu: I Use the Power of Darkness to Save the World

(Decisive in killing + dark and refreshing text + apocalypse + arrogance + refusal of internal friction + Cthulhu + not brainless and refreshing) The low-level protagonist, who lives an ordinary existence, originally just wanted to survive in troubled times, but unexpectedly obtained the most primitive and ancient dark origin bloodline. This forbidden dark bloodline was fused into the protagonist's body by accident. Since then, ordinary mortals have shed their mediocrity, harnessed the power of eternal darkness, and embarked on the path to the extraordinary.