(Demon Instinct. Final and English Ver) First book of Demon Instinct. For centuries, the Kingdom of Silveria stood unmatched-its power unrivaled, its lineage blessed by the divine. But all of that ended when Kohaku III, the strongest warrior of his era, perished in battle. His death signified not just the fall of Silveria's noble bloodline but the start of an era where its enemies thrived in his absence. At least, that's what the world believes. In truth, Kohaku III-once known as The Walking Catastrophe of Silveria did not perish. He survived, hidden in the shadows, changed his name, and trying to abandon his past. Now, under the alias Kouna, he lives in obscurity, far from the battlefield, hoping for a life of quiet anonymity.

A little princess, born under the shadow of treachery is abandoned by those who should have protected her. Her father, the Emperor, whose blood flows in her veins turns on her, accusing her of sins she never did. Her husband, once a romantic figure, turns out to be a coward who uses her as a pawn to gain power. In the end, she is sentenced to die. But fate does not end with death. Reincarnated, she returns in the same body but with a vengeful heart. In a world that once betrayed her, she finds herself back inside the brothel, surrounded by people who care for her in the past life. However, even in this second existence, the palace's shadow remains and the pursuit of power persists. Now back with her mother, she tried her best to fight fate with all of her power, vowing never to return to the cold, cruel castle. She is no longer just the emperor's daughter; she is a natural force determined to erase the history that wrecked her. All she needs to do is flee from the red flag and find a way to live a happy life.

Neptune appears to have everything: brilliance, beauty, and devoted friends who would do anything for her. However, underneath her seemingly flawless existence lurks a darkness that no one else can see. Neptune spends her days feeling caught between life and death, haunted by her parents' inexplicable deaths and a persistent sense of emptiness from which she cannot escape. As her mental condition deteriorates, odd events begin to occur around her-shadows shifting in empty rooms, whispering voices that only she can hear, and vivid nightmares that transport her back to a history she does not completely comprehend. Her friends, Nerei and Laome, attempt valiantly to aid her, even as Neptune withdraws, hanging on the edge of a world she no longer recognizes. But the more she draws away, the closer she gets to discovering the truth: that the darkness around her may not be confined to her head. It's a far deeper power, linked to her family, her past, and the exact reason she was left alone. As she delves further into her own and her parents' memories, Neptune confronts a terrifying question: what if her very existence is the reason of her pain?