Reborn As An Extra In My Own Novel

The moment Leona Onazatella accepted the duel, the torches on the dungeon walls flared with blue light, casting twin shadows behind the knight and the boy.

Kai didn't waste another second.

He bolted forward, mana igniting around him like a halo of violet fire, his katana slicing through the dust-thick air.

Steel clashed with steel. The force of the impact sent shockwaves that cracked the stone beneath their feet.

Leona parried smoothly, her blade singing as it deflected his strikes one by one. Every blow she blocked felt as if carved from divine instinct. Her strength, even while restrained, towered far above Kai's.

She struck back—a horizontal arc meant to decapitate.

Kai ducked, rolled, and countered with a backward slash. It grazed her armor but didn't pierce it.

She was faster. Stronger. And even though she seemed to be holding back, Kai was barely hanging on.

Still, he kept fighting.

Ever since his battle with Deerheart, Kai had felt something forming within him. And with Neko-sensei's guidance, he soon realized it was his prana taking shape.

Kai loosened his muscles and tapped into that invisible force. Instantly, his lilac-colored mana began to shift until it turned bright violet—even his glowing lilac eyes changed to match the hue.

Kai then coated the outer layer of his skin with mana.

His threads spun invisibly in the air, weaving into his limbs and reinforcing his joints.

The invisible threads around him coalesced into a spell of hellfire. He twisted his body ever so slightly, sending the flames toward Leona, who was behind him.

The knight didn't dodge the elemental spell, as if to demonstrate her strength as a knight.

She seemed to grin beneath her mask, savoring the feeling of a proper duel.

With each clash, her demeanor brightened, and glimpses of her memories flashed before Kai.

The bleached moon knight. The captain of the Moonlight Knights.

Her days of happiness. Her bloodied past.

Kai could feel all her emotions—all her burdens.

Honestly, it was too much for him to bear. The pain and suffering were unlike anything he had ever felt.

Her sword, forged from the purest steel and soaked in demon ichor.

Voices that called her from the abyss. All the sleepless nights she endured, blaming herself for the deaths of her people.

Times when she sacrificed those she loved just to save even one more person.

Kai whispered under his breath as they exchanged dozens of strikes in seconds. "I'm sorry."

Leona staggered—only for a breath—but it was enough.

Kai spun, swinging the katana upward and sending her flying toward the ceiling.

He lunged into the air, using his threads to raise one of the swords from the surrounding statues and lifting it above Leona's head.

The knight twisted her entire body, breaking the massive marble blade into debris and using one of the chunks as a second foothold.

Kai dodged the falling debris and leapt again, stepping onto the largest fragment that was inches away from striking him.

Leona raised her blade to slash Kai, but he already knew that would be her move.

He raised his arm, trapping her blade between it, and pierced her armor.

Blood dripped down the katana as Leona's other hand gripped his shirt tightly.

Kai's eyes widened, but in less than a second, she flung him into the air and kicked him with both legs as hard as she could.

His body twisted uncontrollably, the wound he had barely closed with weaving reopening again.

He flew at an impossible speed, crashing through the far wall of the dungeon.

His arms felt limp, and his body felt as if it couldn't move a single extra step.

Kai coughed up blood and looked up at the approaching figure, who raised her blade, ready to finish the fight.

Struggling to laugh, Kai realized something quite silly.

All this time, he had been fighting an unfair fight.

Yes, Leona was far stronger than him, and she had reduced her strength to match his.

Even so, he was fighting someone in armor while wearing nothing but mundane clothes.

Kai coughed more blood. His ribs screamed, his lungs barely functioned.

Leona looked down on him, then brought her leg down in a crushing kick that shattered the earth below.

She tilted her head, staring at the now-empty space.

In that split second, Kai had used his threads in a different way than ever since gaining weaving.

This time, he wasn't controlling other things… He was controlling his own body.

Kai formed threads and moved them through his body, like a puppet or marionette.

Summoning the cube Gimli had handed him, Kai slammed it into his chest.

A bright light exploded outward, making Leona stagger backward, shielding her eyes from the blinding brilliance.

As the light died down, a single figure stood at its center, invisible silver-violet threads weaving around his body.

Kai stood tall, encased in a high-tech combat suit—blacker than night, accented with glowing teal lines. The faceplate resembled a flat gas mask with no air holes, instead inscribed with intricate lines.

On his neck, a tether formed—a brightly colored pale lilac rose.

Kai could feel power surging through his limbs. His arms felt lighter, even though he wasn't directly controlling them.

"Now," he said as he raised his blade, "let's start again."

Leona's visor gleamed. She lifted her sword into a formal knight's salute.

Kai could have sworn she was smiling behind the helmet.

Before he could process it, they clashed again.

Faster. More brutal.

Kai blinked mid-strike, reappearing behind her. Leona twisted to meet him, parrying in reverse.

Sparks exploded between them. Kai swung from the side—Leona ducked and jabbed upward.

A cut opened across Kai's flank.

Still, he weaved more threads, sealing the wound and moving his body with precision.

'Faster... faster,' he thought, swinging his blade from left to right.

His blade, for a brief moment, pierced through her armor. In an instant, she found herself flying toward the wall behind her.

Kai lunged forward, appearing beside her, and with a slash from his katana, tore through her armor.

His violet eyes burned fiercely, his mana and subtle prana stabilizing.

Leona twisted her body, sending her blade downward like a sledgehammer.

Kai couldn't dodge. Instead, he formed a bright violet barrier over his head, wisps of steam escaping the lines on his mask.

He pierced the blade further into her stomach as she brought hers down, slowly cracking his barrier.

But he didn't care at that point. A loud scream echoed through the dungeon as he poured nearly all his mana into the singular attack.

Just as the blade was about to pierce through the other side of Leona's body, her blade shattered his barrier, slamming Kai deeper into the floor.

His grip on his blade loosened, his hand slowly falling to the ground.

Leona breathed heavily, clutching her now-injured stomach tightly. 'This... this human,' she mused.

But Kai wasn't finished.

A dark, broken chuckle escaped his lips.

He raised his hand as threads spun above him, close to the ceiling—each one connecting to floating droplets of prana, mana, and even remnants of his own aura.

Thousands of tiny specks shimmered above him, becoming visible with each passing moment, like droplets of water suspended in air.

He swirled his broken arm, weaving them into a single, massive orb—a ball of liquefied energy, dense and churning like a captured star.

Kai whispered a command. "Fall."

The ball began spinning at an uncontrollable rate as Leona's eyes beneath the armor widened in shock.

Then it launched forward.

Slamming into Leona like a meteor. Her armor cracked under the impact, her prana scattered, her legs buckling.

Kai wasn't done yet—he wouldn't give her the chance to recover.

Gritting his teeth, he stood, using his last remaining energy to lunge forward in a flash. With all his strength, he slammed his katana flat against her helmet.

She flew into the wall, crashing to her knees as cracks spiderwebbed from the point of impact.

Her blade fell.

Kai struggled to stay on his feet, blood spilling from his suit's seams.

Leona raised her head slowly.

Cracks formed across her helmet.

The helmet cracked more—then shattered, blood spilling from her forehead.

Bright blonde hair cascaded like threads of moonlight. Her twin emerald eyes still carried life, staring intently at him. Dark circles rimmed them, but even that couldn't obscure her beauty.

"I yield," she said softly, her voice no longer distorted by metal.

She placed both hands on her knees and bowed.

"I, Leona Onazatella, daughter of King Arthur, Captain of the Holy Knights... hereby pledge myself to you." She smiled softly. "My blade is yours, Master."

Kai smiled back as his vision blurred.

[You have conquered: Leona Onazatella—Star Of Ruin]

[You have earned a Mage Saint]

[You have obtained the Demon Slaying Sword]

[Title obtained: Bleached Moonlight]

Kai stared at the system notification one more time before his legs gave out.

The floor rushed up to meet him.

Then, darkness.