The Demon king's Last oath

The storm rolled in with an unnatural fury. By nightfall, the sky was choked with dark clouds, and the wind howled through the estate like a living thing. Rain lashed against the windows, and the air was thick with tension.

Caius stood by the window of his room, his blue eyes fixed on the storm.At this time he was 15 year old. The pull he had felt all those months was now a deafening roar in his mind, warning him of what was to come.

"It's here," he thought, his fists clenching at his sides.

A knock at the door broke his concentration.

"Come in," he said without turning.

The door creaked open, and Julian stepped inside, his golden hair damp from the rain.

"Caius," he said, his voice unusually quiet. "Father wants everyone in the hall. He says the storm might bring trouble."

Caius turned, his gaze softening as he took in his brother's worried expression. "I'll be there soon."

Julian hesitated, then nodded. "Don't take too long."

As Julian left, Caius grabbed his cloak and threw it over his shoulders. His heart was pounding, but not with fear. It was something else—something primal, urging him to act.

"They're coming."

The grand hall was alive with tension. Servants scurried about, securing shutters and checking lanterns. The Marquess stood near the hearth, his imposing figure silhouetted against the flames. Lady Helena sat nearby, her hands folded tightly in her lap, while Lucian and Julian stood by the door, their postures rigid.

When Caius entered, the Marquess's sharp eyes immediately locked onto him.

"Good. You're here," the Marquess said.

"What's going on?" Caius asked, though he already knew the answer.

"There's something… wrong with this storm," the Marquess admitted. "The guards have reported strange noises coming from the forest. Howls, like wolves, but… different."

Lucian's expression darkened. "Shadowborn."

Lady Helena gasped. "Lucian, don't say such things."

"It's true," Lucian insisted, his gaze shifting to Caius. "We saw one in the forest before, remember? And now, this storm… It's not natural."

Caius remained silent, his expression unreadable.

The Marquess frowned. "Whatever it is, we'll face it. The estate is well-fortified. Nothing will get past the guards."

As if in answer, a deafening roar echoed through the night, shaking the very walls of the estate. The servants froze, their eyes wide with fear.

"What was that?" Lady Helena whispered.

Before anyone could respond, a guard burst into the hall, his face pale and his armor drenched.

"My lord!" he cried. "Something's attacking the outer gates! It's… it's not human!"

The Marquess's jaw tightened. "Lucian, Julian, stay with your mother." He turned to Caius. "You too."

"No," Caius said quietly.

The Marquess blinked, caught off guard by the defiance in his youngest son's voice. "Caius, this isn't a discussion."

Caius met his father's gaze, his blue eyes cold and steady. "You can't stop this alone."

Another roar shook the estate, and the sound of shattering wood echoed through the halls.

"They've breached the gates," the guard said, his voice trembling.

The Marquess cursed under his breath. "Stay here," he ordered, grabbing his sword and heading for the door.

Lucian followed immediately, his own blade drawn. "I'm coming with you."

"Lucian!" Lady Helena cried, but her son was already gone.

Caius hesitated, torn between staying and following. Then he felt it—a presence, cold and familiar, moving closer.

"It's here for me. If I stay, they'll all die."

Without another word, Caius slipped out of the hall, leaving Julian to call after him in vain.

The courtyard was a scene of chaos. Rain poured in torrents, lightning illuminating the shattered gates and the bodies of fallen guards.

In the center of it all stood the creature. It was massive, its body a writhing mass of shadow and claws, its red eyes burning with malice. Around it, smaller Shadowborn prowled, their glowing eyes cutting through the darkness.

The Marquess and Lucian stood side by side, their swords raised, but even from a distance, Caius could see the fear in their stances.

The creature roared, its voice shaking the very ground. The smaller Shadowborn charged, and the battle began.

The guards fought valiantly, but it was clear they were outmatched. The Shadowborn moved like living shadows, slipping through defenses and striking with deadly precision.

Caius stepped forward, his cloak billowing in the wind. He could feel the power rising within him, a force that burned and surged, demanding release.

Lucian spotted him first, his eyes widening in shock. "Caius! Get back inside!"

But Caius didn't stop. He walked toward the center of the courtyard, his small frame cutting through the chaos like a knife.

The creature turned to him, its red eyes narrowing.

"Caius…" it hissed, its voice dripping with malice.

The Marquess froze, his sword halfway through a strike. "It knows your name?"

Caius ignored him. His eyes locked onto the creature, his calm facade finally breaking. "You shouldn't have come here."

The creature chuckled, a deep, guttural sound. "You cannot escape what you are. You belong to the shadows."

Caius's blue eyes began to glow, the faint crimson hue growing brighter. "Not anymore."

He raised his hand, and the storm seemed to pause, the air thick with power. Flames erupted from his palm, dark and twisted, illuminating the courtyard with an unnatural light.

The creature roared, recoiling as the flames lashed out, consuming the smaller Shadowborn in an instant.

Lucian and the Marquess stared in stunned silence as Caius stepped forward, the fire coiling around him like a living thing.

"This is your only warning," Caius said, his voice low and filled with authority. "Leave, or be destroyed."

The creature hesitated, its shadowy form trembling under the weight of Caius's power. Then, with a final, guttural snarl, it turned and fled, disappearing into the storm.

The courtyard fell silent, save for the sound of rain.

Caius lowered his hand, the flames flickering out. He turned to find his father and Lucian staring at him, their expressions a mix of shock, fear, and confusion.

"Caius," the Marquess said, his voice unsteady. "What… are you?"

Caius looked at him, his blue eyes dimming back to normal. "Someone trying to protect his family."

Without another word, he turned and walked away, leaving his father and brother to process what they had just witnessed.