The seventh wolf‑princess Serena is sacrificed to the abyss by her father, sister and fiancé. In desperation she bonds with the forbidden Blood‑Moon Reaper system, gaining power at the cost of her lifespan by devouring foes’ bloodlines. Under the alias Grey‑Claw she exacts revenge in the arena, meets the mysterious Kane, uncovers the ancient conspiracy of the torn wolf‑ancestor and royal sacrifices, and finally rejects divinity to shatter the blood‑line curse.
