Awakening in a world where the very rain falls as fire and the sky is bruised with shades of black and red, the former hero Simon begins his second life at the absolute bottom of the food chain. For fifteen years, he endures the crushing weight of poverty within the declining Duskfang Tribe, watching his self-sacrificing demon mother, Lyssa, slowly wither away from starvation. Refusing to succumb to a slow and pathetic death, Simon utilizes his feline agility, silent footwork, and tactical brilliance to initiate a series of daring, high-stakes robberies against the tribe's corrupt elite, single-handedly destabilizing the local economy while securing vital sustenance. His criminal exploits reach a thrilling climax when a legendary Daegrin merchant named Zaglur arrives to trade in desperate commoners, presenting a collection of rare artifacts and a priceless vial of Devourer's blood essence. Sensing a golden opportunity to shatter his physical limitations, Simon orchestrates a chaotic distraction during a slave auction, successfully snatching the mythical blood essence from under the nose of the powerful merchant. He retreats to his hovel to absorb the stolen treasure, utilizing his Seven Stars Blessing to assimilate the terrifying active skill known as Devour rather than directly altering his physical form, which would have exposed his theft. But the cruel nature of his new reality strikes immediately after he completes his breakthrough. As his consciousness returns, he does not find freedom, but the cold weight of heavy iron chains binding his limbs. Standing before him is the merchant Zaglur, accompanied by his mother, Lyssa, who holds a pouch of glittering crystals and wears an expression of profound guilt, having ruthlessly sold her own son's life for a chance to escape her miserable existence. This devastating betrayal shatters Simon's lingering humanity, forcing him to accept that in this dark realm, survival demands absolute ruthlessness, even as Zaglur drags him away like a dog into the dangerous wilderness. As they embark on their journey, Simon realizes that his captor plans to execute a horrific extraction process that will likely end his life.

Dragged through the dangerous wilderness of the Wildlands, Simon is forced to accompany Zaglur toward an unknown destination where the merchant intends to extract the Devourer's blood essence. However, their journey is violently interrupted when they stumble upon a scene of absolute carnage, discovering the slaughtered corpses of Zaglur's hired mercenaries. Before they can react, they are ambushed by elite shadow assassins known as Velaris, sent by the powerful Shadowgrave Clan to claim the ancient bloodline for themselves. A catastrophic battle erupts as Zaglur unleashes a barrage of high-level artifacts, bending space and time to combat three Greater Demons who seek his life. Amidst the chaotic crossfire, Simon is forced to defend himself against a sadistic assassin, utilizing his newly acquired Devour skill on the corpse of a fallen mercenary captain to temporarily boost his physical capabilities to the level of a Fiend. Despite his valiancy, the arrival of a terrifying Demon Lord utterly shifts the scales of power, as the entity easily bypasses Zaglur's defenses and impales the merchant with a divine dagger. Recognizing his imminent demise, Zaglur chooses to deny his betrayers their ultimate prize, tossing the legendary Miser's Ring to Simon and opening a desperate spatial rift to facilitate the boy's escape. But before Simon can leap through the shimmering portal to freedom, the cold hand of the Demon Lord clamps down upon his shoulder, dragging him back into the shadows as the rift collapses into nothingness. Bound and helpless once more, Simon is transported to the deepest dungeons of the Shadowgrave Clan, where an agonizing extraction ritual awaits him under the supervision of cold-blooded masters who view him as nothing more than an expendable vessel. The transition from captive of a greedy merchant to a prisoner of an organized, secretive assassin syndicate marks a massive escalation in danger, as Simon must now face specialized extraction arrays designed to tear the very soul from his flesh. The spatial tear collapses behind him as the Grave Lord's icy grip solidifies his fate, sealing him in a destiny of captivity.

Imprisoned within the subterranean obsidian fortress of the Shadowgrave Clan, Simon is subjected to an agonizing extraction ritual designed to siphon the Devourer's blood essence from his body. Chained to a central pillar covered in glowing chaos runes, he endures excruciating pain as black needles pierce his spine, drawing his blood out in a crimson mist. However, the ritual yields unexpected results when Simon's bloodline resists, mutating into a mysterious indigo hue rather than the expected black coloration of the Devourer. Frustrated by the failure, the Grave Lord hands Simon over to Pellin, a sadistic, bloated pig demon who serves as the clan's chief torturer. What follows is a descent into absolute madness as Pellin subjects Simon to horrific physical and psychological torment, culminating in the insertion of a soul-eating centipede into his ear. Throughout this nightmare, Simon's human-honed willpower and his Fearless skill keep his sanity intact, preventing his mind from breaking under the pressure. His unnatural resilience catches the attention of the clan's high-ranking Veilmasters, who intervene to halt the torture, recognizing that Simon possesses a terrifying, anomalous potential that could be of immense use to the clan. He is healed and prepared for the upcoming Coming of Age Rite, where he must awaken his demonic heart and prove his worth to the merciless masters of the shadow realm. This survival marks his first major victory against the clan's attempts to break him, establishing him as an enigma who refuses to play the role of a victim. As he is cast into a barren chamber to recuperate, he realizes that the upcoming trials are not just a test of survival, but a gateway to acquiring the dark cultivation resources he desperately needs to rebuild his power. He must now prepare to face the other candidates, who view him with disdain due to his mixed heritage, unaware of the sleeping giant within him. He must learn to harness his newly awakened chaos flame to navigate the complex political landscape of the Shadowgrave Clan.

Entering the brutal trials of the Blackwind Valley alongside over a thousand arrogant candidates, Simon finally awakens his demonic heart, attaining a Flickering Heart at the Minor Lesser Demon rank. Despite his low cultivation level, his combat experience and feline senses allow him to navigate the treacherous environment with ease, easily outperforming his noble-blooded peers. During the trials, he is forced to confront a group of arrogant candidates led by Jath, who seek to eliminate him out of pure spite. Utilizing his veteran instincts and his Devour skill, Simon orchestrates a terrifying game of Simon Says, ruthlessly executing his tormentors one by one in a display of absolute dominance and psychological warfare. His path crosses with Thorgan, a mysterious orphan possessing a rare Royal Bloodline, and together they are forced to confront a powerful, berserk Three-Tailed Alpha Shadow Wolf. As the beast unleashes its devastating shadow attacks, Simon must decide whether to abandon his temporary ally or unleash the full extent of his hidden power to slay the creature. This decision will determine his standing within the clan and his future as an assassin. Before this confrontation, Simon's sharp senses lead him to a hidden underground chamber containing the remains of Hell's Sword Daemon, where he acquires a massive spatial ring, a powerful mask, and a secret sword art. This hidden inheritance provides him with the ultimate trump card, but also saddles him with the burden of an ancient, unseen conflict. Now, standing side-by-side with Thorgan against the raging Alpha Wolf, Simon must balance the preservation of his secrets with the immediate necessity of survival, knowing that any slip-up could expose his anomalous nature to the watchful eyes of the Shadowgrave Veilmasters. With his newly acquired sword art and the support of a royal-blooded ally, Simon prepares to carve his name into the annals of the shadow realm.