Lin Shu sat alone inside the secured room he had rented, the only place he trusted where no one could spy on him. On the table before him lay the Thunderforge pills he had crafted days ago, their faint silver glow humming with suppressed energy. Beside them gleamed surgical blades, clamps, bone needles, and glass vials. And at the very center, preserved in jade containers, rested two thunder eagle hearts—one male, one female.
The male's heart was larger, throbbing faintly even in death, saturated with violent power. The female's was weaker, but still far beyond anything human. Lin Shu decided he would not risk his own body first. He needed a trial subject. That morning, he had walked through the black market's shadowed alleys, ignoring the stink of blood and rot, until he found what he wanted: a slave.
Most of them were the wreckage of war—defeated village men, broken clan remnants, or failed cultivators. None above mid-stage Rank 1. Lin Shu had chosen carefully, purchasing a healthy low-stage cultivator. Strong enough to endure the process, weak enough not to resist even if the impossible happened and he broke free from the enslavement seal.
To avoid suspicion, Lin Shu had dressed the man in clean robes, passing him off as a private instructor. No one would question a youth keeping a teacher hidden away. After all, only one of them would walk out alive.
When they returned, Lin Shu wasted no time. He knocked the man unconscious with a precise strike, shackled his limbs and neck with iron cuffs, and dragged him onto the surgical table.
The operation began.
Lin Shu first crushed a Thunderforge pill into powder, mixing it with alchemical fluid until it became a glowing, volatile paste. He sliced into the thunder eagle's heart, the scent of scorched iron and storm filling the room. With careful hands, he extracted the remaining essence, refining it into a thick, crackling elixir that hissed like liquid lightning.
His bone-needle syringe trembled as he drew the substance in. The vial glowed white-blue, arcs sparking across its surface.
Without hesitation, he cut open the slave's chest, exposing the man's trembling heart. The smell of blood filled the room, hot and suffocating. Lin Shu guided the needle in and injected the thunder eagle's essence directly into the organ.
The man convulsed violently, his back arching against the restraints as lightning ran across his veins. His heart beat like a drum, faster and faster, until it roared like a thunderclap. For a moment, Lin Shu thought the subject would simply explode—but then the body stabilized. Breathing slowed. The heart adapted.
The operation had succeeded.
But the restraints began to groan.
The slave's eyes snapped open, glowing faintly with lightning. His muscles bulged, cords of power surging through him as the cuffs snapped like brittle twigs. He tore himself free, standing tall with trembling shock on his face.
"My strength…" he whispered, staring at his hands as if they belonged to a warlord.
He didn't have time to finish the thought.
Lin Shu slammed him back to the ground with merciless force, planting a boot on his chest. His arms shot downward, and from his palms erupted two arcs of thunder.
The bolts ripped into the man's face, searing flesh and bursting eyes in an instant. His skin cracked apart, bone glistening beneath charred muscle. He screamed, clawing at the floor, but his body still clung to life.
Lin Shu only smiled.
This was proof. Even after taking the full brunt of a Rank 1 mid-tier technique, the man still lived—broken and dying, yes, but alive. That meant with the male thunder eagle's heart, Lin Shu could endure more. Perhaps even a mid-tier strike without crippling injury.
The slave's body writhed pitifully, his life ebbing away. Lin Shu crouched down, slipped his clawed bone gauntlets over his hands, and ended it. He tore through the man's throat with brutal strikes until the gurgling stopped, leaving only silence and the faint stench of scorched blood.
Lin Shu stood over the corpse, eyes cold, lips curling into the faintest smile. The true operation would come soon.
And this time, it would be on himself.
Lin Shu washed his hands, his gaze cold and steady as he turned toward the second table. This one was meant for him alone. The male thunder eagle's heart lay there, pulsing faintly even though it had been dead for a few hours, preserved by the concoctions he had soaked it in. Compared to the female's, this one was thicker, denser, the veins running across it like living lightning channels. Just being near it made the air crackle, the faint smell of ozone spreading through the chamber.
He placed the Thunderforge pills beside it, three of them, their glossy surface flickering faint arcs of light. Each was the result of sleepless nights, countless failures, and risk. Now, they would either make him ascend or destroy him.
Lin Shu unfastened his robes until his chest was bare. He strapped himself down with leather belts across his arms, legs, and torso—not out of fear of failure, but because he knew his body would thrash uncontrollably under what was about to happen. His breath slowed. His heartbeat steadied.
He took a scalpel from his prepared surgical tray. Without hesitation, he cut a clean, precise line across his chest, the blade sliding between skin and muscle. Pain flared white-hot, but he neither winced nor faltered. Slowly, methodically, he pried open his own ribcage using steel clamps, the sound of cracking bone echoing through the room. Blood streamed, but he had prepared an array of medicinal herbs that coagulated and slowed the loss. His own heart, strong from body refinement, beat heavily in the open air.
He swallowed the first Thunderforge pill. His Qi churned violently, lightning crackling along his veins, his chest trembling with each heartbeat. He forced the thunder eagle's heart into a bronze basin filled with his prepared elixir—a dense, glowing mixture of medicinal roots, molten ores, and lightning-charged water. Slowly, the heart melted down into an essence that pulsed like liquid thunder.
Lin Shu drew it into a large syringe forged of tempered jade and steel. His hands were steady as he pierced his own heart with the needle and slowly injected the thunder elixir directly into it. The reaction was instant.
His body convulsed violently against the restraints. Lightning arced from his chest, scorching the ceiling and walls, burning black marks into the stone. His heart pounded as if it wanted to burst, every vein bulging under the strain. His bones cracked, skin split open in jagged streaks as if lightning itself was carving through him.
The second Thunderforge pill he bit down on, crushing it between his teeth before swallowing. His Qi channels screamed, writhing as thunder flooded them, threatening to tear apart his meridians. He could smell his own flesh burning from within. Blood leaked from his eyes, ears, and mouth, sizzling with sparks.
Then came the most excruciating part. His original heart fought against the thunder eagle's essence, clashing in a deadly struggle inside his chest. It thrashed, beating faster and faster, threatening to rupture. His vision blurred. His lungs convulsed as if suffocating. The restraints creaked as his body slammed against them again and again.
But Lin Shu gritted his teeth and endured. "Break… or be reforged," he muttered, his voice hoarse yet steady.
The third Thunderforge pill dissolved in his stomach, merging with the essence inside him. His heart finally convulsed, then—changed. A single, deafening thunderclap erupted from within his chest, shaking the entire chamber. His ribs glowed faintly, as if reforged by lightning. His veins no longer bulged in protest; instead, they hummed with controlled power. His heart no longer beat like a human's—it pulsed like a thunder drum, steady, powerful, crackling with caged lightning.
Smoke rose from his body. His breath was ragged, yet his lips twisted into a faint smile. The pain was unbearable, but he endured it. He had done it.
Lin Shu had forged the final step the stage of the Storm Heart of the Thunderforge Physique.
Lin Shu looked down at his body, his breath heavy, his eyes sharp. A storm roared inside him. Power far beyond anything he had ever touched coursed through his veins. He clenched his fist and drove it into the floor—stone cracked under his knuckles, spreading into a spiderweb of fractures that reached the edges of the chamber.
He moved before the dust settled, sprinting into the training chamber with all his speed. He wasn't using a single technique, and yet his body moved faster than when he used Lightning Steps. His muscles hummed, his bones thrummed, his very blood seemed to spark with thunder. Each stride carried the weight of lightning, and every exhale felt like a storm breaking loose.
His ivory dominion stirred. From the back of his hand, a white blade of bone pushed outward, smooth and merciless, curving like the talon of a predator. Lightning danced along its edge, coiling around it as if the heavens themselves had claimed his bones as conduits. With a single slash, he carved through the ground—stone parted cleanly, sharper than any blade he had wielded before.
He could feel it clearly now—the Thunderforge Physique. His bones were denser, his flesh tougher, his frame reforged in the crucible of storm. With a thought, he summoned his armor. The ivory plating encased him, pale and dreadful, and he tested its strength by hurling his own Thunderbolt Arc against it. The impact cracked across the chamber, a violent flash illuminating the walls. When the smoke cleared, his armor bore only faint scratches where it should have splintered. Lin Shu's lips curled upward. This strength… this was no mere refinement. This was a rebirth.
But the true terror of this art was not its resilience. It was the technique woven into its marrow—Lightning Fang Surge.
He stood still, letting his body draw in the storm. Thunder gathered within him, compressing into his limbs, forcing his muscles to tense until they trembled. Sparks crawled across his arms, then exploded into arcs that wrapped his forearm like a predator's talon forged of pure lightning. The pressure was immense, unbearable—if he kept it caged, it would tear him apart from the inside.
So he let it go.
The surge detonated. A beam of thunder erupted from his arm, slamming into the ground with a roar that shook the chamber. Stone shattered, the floor split, and when the smoke and dust cleared, a crater more than ten meters wide scarred the ground. Lin Shu stood at its edge, lightning still dancing along his flesh.
His chest rose and fell with ragged breaths, but his grin stretched wide, nearly splitting his face. He had touched something beyond the reach of ordinary Rank 1 cultivators. This was a power even heirs of clans could not dream of—not without exhausting their pitiful Qi reserves.
But Lin Shu had no such weakness. This technique demanded no Qi at all. It fed on the lightning that his body naturally generated, lightning that would build again and again until he was ready to unleash another storm. Fifteen minutes. That was all it would take before he could release another strike like that.
He threw back his head and laughed, the sound echoing like a mad hymn through the ruined chamber.
"Hahahahahaha! Finally… a true trump card! A weapon that rivals the bloodlines of so-called prodigies! Even their clans cannot grant them this! As long as they crawl beneath the peak stage, they will never wield a technique like this. But I—" his grin sharpened as the last sparks died around him, "—I will always have the storm at my side. I will always have the fangs of thunder."