Welcome to a world where blood, lust, power, loyalty, and desires to kill are taken to their limits.

Out of the darkness where that man's lust for power is allowed to exist, the unimaginable emerged. From the forgotten legends of ancient times, they have been called forth into the world once again—devils. From within the shadows, rogue hunters arise, operating for their own reasons but aiming for the same goals. The devils do not walk unchallenged. Terror doesn't flourish without resistance, and a battle for survival erupts.

An age that changed from peace to violence and sin, trading blood for blood, humanity may be lost. But from the ashes of destroyed hope, a new legend emerges, a figure harbored by death, respectfully feared by devils, and distrusted by humanity. A stolen child who became a devil slayer and who became a devil, his name is Heartnik.

Try to kill me if you can, but ready or not, I'm coming for you.