Bloodbound Codex: I Grow Stronger in Secret

The crimson glow around the Sanguis Stylus deepened as the last strands of blood were pulled from the Hybrid Muxical’s corpse.

The blood did not flow naturally. It stretched through the air in thin streams before being absorbed into the crystal body of the stylus. The monster’s massive corpse twitched once, then became still. It looked different after that. Not only dead, but emptied, as if the stylus had stripped away more than what should have been possible.

Atlas remained collapsed on the ground.

His breathing was uneven, and his body was still trying to recover from the fight. The Hybrid Muxical had almost killed him. He had killed it first, but the cost had been high. His left arm was ruined, his blood had soaked the stone beneath him, and every part of his body still carried the pressure of the attributes he had forced into it.

His left arm twitched slightly.

Pain followed immediately.

Atlas clenched his teeth and pressed his right hand against the ground to keep himself steady. He did not have enough strength to move properly yet, but his mind forced itself to observe. The Codex had shown one rule after another since he woke up in the lower chamber, and every rule mattered if he wanted to survive.

His eyes stayed on the corpse.

”...It actually pulled in the blood from the Muxical?”

His voice was hoarse.

”Not just a little...”

He swallowed faintly.

”All of it?”

The corpse answered nothing. It only lay there, drained and hollow. A B-Rank monster that had nearly torn him apart had become nothing more than a blood source for the Sanguis Stylus.

Atlas looked toward the Codex.

The book floated nearby with the same calm presence as before. It did not react as if anything strange had happened. To the Codex, taking blood from a dead monster seemed no different from taking blood from Atlas.

”...What kind of relic even does something like that?”

His gaze shifted to the first page.

[ PROFILE ]

Then lower.

[ Note: User must fill the blanks using the Sanguis Stylus. Ink source: Blood. Locked fields will open upon reaching current limit. ]

Atlas read the note again, slower this time.

The line had never said the blood had to be his.

Only blood.

The Codex used blood as ink. The Sanguis Stylus could take blood from him, and now it had taken blood from the Hybrid Muxical. That meant every monster in the ruin was not only a threat anymore.

They were fuel, Blood fuel.

Atlas looked at the corpse again.

The thought was simple, but the implication was huge. If monster blood could be stored and used for writing, then his growth did not depend only on how much blood he could afford to lose. He could hunt, collect, write, improve, and hunt again. The Codex had turned survival into a cycle.

Then Atlas looked at his left arm.

It still hung unnaturally, crushed from the Hybrid Muxical’s bite. Flesh had torn, bone had broken, and blood continued dripping slowly onto the ground. Pain pulsed through it every time his heart beat.

His expression tightened.

”...Wait.”

Another rule came back to him.

When he woke in the darkness, the hole in his stomach had disappeared, When he wrote Agility, his shoulder had sealed enough for him to move.

When he wrote Stamina during the fight, his body had stabilized and repaired!

Every time he filled or raised a stat, his body changed.

Atlas looked from his broken arm to the Codex.

’Does that mean...?’

He did not finish the thought.

There was only one way to test it.

His right hand reached for the Sanguis Stylus. His fingers closed around it with a tremble. This time, the tremble was not only from pain. It came from understanding what might happen if his guess was right.

The Codex drifted closer.

The first page remained open.

Strength: 9 [ LOCKED ] [ LOCKED ]

Stamina: 5 [ LOCKED ] [ LOCKED ]

Agility: 5 [ LOCKED ] [ LOCKED ]

Spirit: _ [ LOCKED ] [ LOCKED ]

Atlas’s gaze stopped on Stamina.

The number was no longer blank. He had written it during the fight, and it remained stable. The Codex had accepted it.

His brows pulled together.

”If the blank can be filled...”

His voice was rough.

”Then can the number be raised?”

Atlas exhaled slowly and tried to steady his breathing. The Sanguis Stylus hovered near the Stamina value, filled with the Hybrid Muxical’s blood. The blood inside it was darker and heavier than his own. Whether that mattered, he did not know yet.

But if monster blood worked, this would prove it.

”...Let’s see if this really works the way I think it does.”

He lowered the stylus.

The crystal tip touched the number beside Stamina.

The page resisted but - Not like when he had forced Strength to nine.

The resistance was lower and weaker this time. The monster blood inside the stylus stirred, then flowed toward the tip.

Atlas dragged the stylus carefully.

The old number changed.

Stamina: 6 [ LOCKED ] [ LOCKED ]

The page glitched once.

The locked fields beside Stamina flickered, but the resistance was weaker than before. The number trembled for a moment, then settled completely.

Atlas’s heart slammed hard inside his chest.

THUMP.

THUMP.

THUMP.

For a moment, his breathing broke as pressure spread through his body. His veins pulsed, his muscles tightened, and his jaw clenched from the sudden strain. Then the pressure released.

”Hah—!”

Air filled his lungs properly.

His breathing changed almost at once. It went from broken and shallow to deeper and steadier. The exhaustion did not vanish, but his body gained enough stability to function again.

Then his left arm moved.

Atlas froze.

The broken bones realigned first, snapping back into place under the skin with a sickening internal pressure, muscle followed, flesh followed. Torn skin pulled together unnaturally fast, sealing over the damage until the arm no longer hung like something half-detached.

Atlas watched the entire process.

His pupils shook as he slowly opened his fingers.

Then closed them.

Atlas swallowed.

’So every time I raise these numbers... it heals me too.’

Instantly.

A faint laugh escaped his throat, unstable and dry.

”...This is insane.”

His fingers clenched.

”No.”

His eyes lifted toward the Codex.

”This is beyond insane.”

He breathed once, then looked at the page again.

”If even one person finds out about this...”

A short laugh slipped out.

”This entire world would go to war over it.”

Atlas forced himself to stand after a moment.

His legs responded better this time. His balance was not perfect, but he could remain upright. The attribute increase had healed the broken arm and stabilized him, but it had not erased the exhaustion of the battle or the memory of pain. That meant healing through the Codex repaired damage, but it did not make him invincible.

He looked toward the corpse of the Hybrid Muxical.

Then toward the darkness beyond it.

The lower ruin was silent again, but now Atlas did not mistake silence for emptiness. Something else could be inside. More monsters. More paths. More chances to die. More chances to gather blood.

He needed an exit.

”...Now...”

His voice steadied slightly.

”How do I get out of here?”

Atlas pulled together everything he knew from overheard conversations, tavern rumors, drunken guards, and scraps of knowledge commoners usually received only by accident. Ruins had rules. Not always the same rules, but patterns existed. Clear a Boss, claim the core, or find a distortion that acted as an exit.

His gaze moved upward, toward the direction where the black monster had been.

”Boss...”

He remembered the faceless creature that pierced him before he could react.

A faint scoff left him.

”Considering how weak I am, even thinking of defeating the Boss of an Eternal Ruin...”

His lips tightened.

”That’s just suicide.”

There was no point pretending otherwise.

Strength 9, Stamina 6, and Agility 5 were enough to survive the Hybrid Muxical after nearly dying several times. Against the black monster above, those numbers meant very little. The monster had ended him before he knew it had attacked.

That left only one option.

”The Hidden Curvature.”

The term sounded unreal even as he said it.

A Hidden Curvature was not a proper exit. It was a flaw in a ruin’s inner space, a distorted bend where the ruin’s structure curved incorrectly and allowed someone to leave without defeating the Boss. Most explorers never found one. Some died searching. Some claimed to have escaped through one and were called liars afterward.

But Atlas had nothing else.

”No way I’m throwing my life away in this damned place.”

His gaze shifted back to the Codex.

”And this relic...”

His fingers flexed slowly.

”This thing...”

He stared at it for a long moment.

”I have to hide it, No matter what.”

That conclusion was obvious.

The Codex could rewrite attributes. It could use blood as ink. It could heal through stat increases. It could absorb monster blood. It had locked pages that even Atlas could not read yet. If the Royals found out, they would hunt him. If nobles found out, they would tear apart cities to claim it. If Revenants found out, they would kill first and ask questions later.

Atlas’s expression darkened.

”No one can see you.”

The Codex floated silently.

Atlas stared at it.

”You...”

His voice lowered.

”Do you understand me?”

No response came.

”Can you hide?”

Silence.

”I mean... can you stay out of sight?”

Still nothing.

”Can you not be seen by others?”

The Codex remained still.

Atlas narrowed his eyes.

”If you’re really this powerful of a relic, then I don’t see any reason why you wouldn’t have something like that.”

For a moment, nothing happened.

Then the Codex snapped shut.

The Sanguis Stylus slipped from his fingers and attached itself to the side of the book as if it had always belonged there.

Atlas’s eyes widened slightly.

Before he could react, both shot toward him.

A streak of crimson light pierced into his chest and disappeared.

There was no impact.

Atlas froze.

”...What was that?”

His hand rose to his chest.

A strange warmth spread through him. It was not healing, not stat growth, and not pain. It felt like something had connected to a place deeper than flesh and bone.

A connection.

Atlas felt it even while he barely understood what just happened.

If he called it, it would come.

A faint smile appeared.

”...So you listen.”

He closed his eyes briefly.

Then spoke.

”Originate.”

The word came out naturally.

Atlas opened his eyes immediately.

He stiffened.

He had not planned to say that. He did not remember learning that word in this context. It had simply come out, as if the connection had placed the command in him before his thoughts caught up.

”...What?”

For a brief moment, he did not move.

’I didn’t think that.’

His fingers twitched slightly.

”Originate...”

He muttered it again, quieter this time.

The Codex emerged.

Crimson light unfolded from his chest, and the book appeared before him with the Sanguis Stylus attached to its side. It hovered in the darkness with the same calm presence as before, as if hiding inside him and returning on command were completely natural functions.

Atlas stared at it with wide eyes.

The Codex had hidden itself inside him.

The word had appeared in his mind.

And it had answered.

That meant the connection was deeper than ownership.

It had reached his instincts.

Atlas’s expression tightened.

”...I’ll think about it later.”

There was no time to dwell on it now.

The Codex opened again.

The first page appeared.

[ PROFILE ]

[ Name: Atlas Mariorett ]

[ STATS ]

Strength: 9 [ LOCKED ] [ LOCKED ]

Stamina: 6 [ LOCKED ] [ LOCKED ]

Agility: 5 [ LOCKED ] [ LOCKED ]

Spirit: _ [ LOCKED ] [ LOCKED ]

Atlas looked at the page and exhaled slowly.

”I’ll get out of this damned ruin.”

A pause followed.

His eyes sharpened slightly.

”But not like this.”

His body was no longer the same as before, but it was still unbalanced. Strength was high, Stamina and Agility were lower, Spirit remained untouched, and his control was almost nonexistent. He had already crashed into a wall because his speed and strength did not match his experience.

”If I’m already here...”

His fingers tightened slightly around the Sanguis Stylus.

”I might as well get stronger before I leave.”

”There are probably so many powerful people in the world, i can’t even count them...”

His gaze locked onto the open page.

”So, while I’m at it...”

The monster blood inside the stylus moved slowly.

Atlas’s lips curled faintly.

”I should test this relic properly.”

And the Codex remained open.