Davidham_

In a world where magic reigns supreme, Ethan Baron , the frail third young master of the prestigious Baron Family, is considered a failure. With his elder siblings excelling in combat and sorcery, Ethan is ridiculed and dismissed. But on the night of his tenth birthday, a forgotten truth resurfaces—he is the reincarnation of the Heavenly Demon King, the supreme ruler of the Murim universe. Along with his memories, he unlocks the Heavenly Demon Magical King System, a power that defies the laws of this world.

Armed with knowledge of martial arts, demonic cultivation, and his new system, Ethan embarks on a path of vengeance and dominance. As he navigates noble conspiracies, clashes with arrogant geniuses, and defies the gods themselves, he will prove that the weakest can become the strongest—and that the world will once again tremble before the Demon King.

Reborn Heavenly Demon

Ethan stood in the open courtyard, his first battlefield in this new life.

The early morning mist lingered in the air as a dozen armored knights sparred in the distance, their swords clashing in rhythmic precision. This was where warriors of the Baron family trained, yet for the past ten years, Ethan had never stepped foot here.

A sharp voice cut through the air.

"Third Young Master, your test will now begin."

Sir Gareth, the Baron family's combat instructor, stood before him. A rugged man with a scar across his jaw, Gareth had trained both Alexander and Selene to mastery. Now, for the first time, he was addressing Ethan.

The knights watching from the sidelines didn't even bother hiding their smirks.

Ethan's grip tightened. He would enjoy proving them wrong.

A knight placed a series of weights before him, ranging from 10kg to 50kg. Ethan was expected to lift them to measure his physical progress.

Just a week ago, lifting even 10kg would have left him gasping for breath.

[Basic Body Reinforcement Activated.]

A subtle warmth spread through his muscles. He crouched, wrapped his fingers around the 10kg weight, and effortlessly lifted it.

Whispers spread among the watching knights.

Ethan took a deep breath and gripped the 50kg weight. His arms trembled slightly, sweat forming on his brow. But after a moment of struggle—

Sir Gareth's expression darkened. "Pass."

Ethan was given a simple challenge—evade five strikes from a wooden sword.

His opponent was one of the junior knights, a man twice his size.

Normally, a ten-year-old noble with no training would be helpless.

As the knight lunged forward, Ethan's eyes flashed.

His opponent's movements slowed in his vision. He could see it—the shifting of weight, the angle of attack, the subtle hesitation in the knight's wrist.

The watching knights stiffened as Ethan effortlessly avoided each attack.

By the fifth dodge, the junior knight lowered his sword, eyes wide.

"…Pass," Sir Gareth muttered, his disbelief evident.

This was the part Ethan dreaded most.

Unlike his siblings, who possessed natural magical talent, his mana had always been weak. But now, with the Heavenly Demon Magical King System, things had changed.

A magic instructor handed him a small mana crystal. "Channel your energy into this."

Ethan took a deep breath and focused.

A faint glow flickered in the crystal. Weak, but existent.

The instructor frowned. "Your magic capacity is still low, but your control is… precise."

Ethan suppressed a grin. In his past life, as the Heavenly Demon King, he had wielded techniques that blurred the line between magic and martial arts. His current ability was pathetic, but his potential? Limitless.

As the tests concluded, the murmurs among the knights had shifted.

Instead, they watched Ethan with a mix of curiosity and unease.

"Your progress is… surprising," he admitted. "Starting tomorrow, you will train alongside the younger knights."

The First Test