Bloodbound Codex: I Grow Stronger in Secret

”Ugh...!”

Atlas woke up because his body forced him to.

For a few seconds, he could not understand what he was seeing. There was no ceiling above him, no torchlight from the upper passage, and no opening that led back to the place where the black monster had attacked him. There was only darkness around him and cold stone beneath his back.

His body felt heavy, but he was not dead. That was the first thing he understood. His ribs hurt when he breathed, his back was stiff, his head throbbed, and his clothes had hardened from dried blood. The pain was still there everywhere, but it was different from before. Before, there had been a hand through his stomach and blood in his throat. Now his body hurt like it had survived something it should not have survived.

That difference made his mind wake faster.

The memories returned one by one.

The black monster. The arm through his stomach. His sword falling. The monster throwing him away. The boulder breaking against his back. The fall into the lower darkness. The monolith. His blood crawling across the stone. The book. The crystal stylus. The page.

**[ LOCKED ]**

Atlas’s hand moved to his stomach.

His fingers pushed under the torn, blood-stiff cloth. He expected to feel an open wound, torn flesh, or at least pain deep enough to make his body curl again. Instead, his fingers touched clean skin.

Atlas pressed harder.

Still nothing.

He pulled the torn fabric aside and looked down at his abdomen. His shirt was ruined, and dried blood covered the cloth and skin around it, but the wound itself was gone. It was not half-healed or badly closed. It was gone.

”...What?”

His voice came out low and rough.

The injury had been real. He remembered the arm passing through him. He remembered the feeling of his body opening around it. He remembered his breath failing and blood filling his mouth. That kind of wound should have killed him, and even if it somehow did not, it should have remained.

A slum-born commoner did not recover from that.

Not without a healer.

Not without a relic.

Atlas slowly lifted his gaze.

A faint crimson-white glow hovered a short distance away.

The book was still there.

It floated above the ground with its dark cover half-closed. Thin crimson vein-like lines moved beneath the surface, slow and faint, like blood flowing under skin. Beside it hovered the crystal stylus, transparent and sharp, with dark red liquid moving inside it.

Atlas looked at the stylus for a few seconds.

That was his blood.

He understood that much. The monolith had opened after drinking his blood. The stylus had filled with his blood. The book had shown its first page after his blood touched it. That meant the relic had a clear rule.

Blood activated it.

Blood filled the stylus.

Blood wrote into the book.

And after all of that happened, Atlas was alive.

Atlas pushed himself upright. His arms trembled under his weight, but they held. His head still hurt, and every movement pulled at bruised muscles, yet compared to the wound that had gone through his stomach, this pain was manageable. He slowly stood, locked his knees when his legs almost gave out, and waited until the dizziness weakened.

Only then did he study the chamber around him.

The lower area was larger than he first thought. Broken pillars stood in the distance, some tilted and some floating slightly above the ground as if this place did not follow the same rules as the upper ruin. The floor was made of dark stone, cracked in several places, but there was no dust, moss, or sign of old footsteps.

This place had not been used.

It had been sealed.

The black monster had thrown him here by force, but the chamber itself looked like something hidden from the rest of the ruin.

Atlas turned back to the book.

Relics were not commoner tools. They belonged to nobles, Guilds, Royal vaults, old families, and powerful Explorers. Some relics healed, some attacked, some protected their owners, and some destroyed their owners if used incorrectly. A normal person might see a relic and feel lucky, but Atlas had grown up in Ormolio’s outer slums. Anything valuable always came with a cost. If something looked useful, either someone powerful owned it already or it would demand something worse later.

And this book had been sealed inside the depths of an Eternal-Class Ruin.

That alone meant it could not be simple.

Atlas took one careful step toward it.

The book reacted immediately. It rose slightly, opened by itself, and turned its first page toward him. A soft light spread from the page, enough to push back the nearest darkness and make the letters clear.

At the top, one word formed.

**[ PROFILE ]**

Atlas narrowed his eyes.

Below it, another line appeared.

**[ Name: Atlas Mariorett ]**

His jaw tightened at the surname.

Mariorett.

It was his name, but it had never protected him. In the slums, names only mattered when they belonged to someone with power, money, or backing. His name had not stopped hunger. It had not stopped guards from treating him like dirt. It had not stopped the old Scout and the Royal soldiers from throwing him into the ruin first.

Still, the book knew it.

That mattered.

The page continued changing.

**[ STATS ]**

Strength: _ **[ LOCKED ]** **[ LOCKED ]**

Stamina: _ **[ LOCKED ]** **[ LOCKED ]**

Agility: _ **[ LOCKED ]** **[ LOCKED ]**

Spirit: _ **[ LOCKED ]** **[ LOCKED ]**

Atlas stared at the page.

The words were simple. Strength, Stamina, Agility, and Spirit. They were the basic factors that decided whether a person could fight, endure, move, and use power. For nobles, these things were developed from childhood with proper food, tutors, training methods, breathing techniques, relics, medicines, and Spirit refinement. For Atlas, they had grown through hunger and necessity.

Carrying stolen sacks before older boys could take them. Running from guards. Fighting with broken wood and rusted metal. Sleeping lightly because someone could cut his throat over bread. That life made a person tough, but it did not make them important.

The page showed blanks beside each attribute.

Not numbers already written.

Blanks.

Waiting.

A smaller note appeared below the list.

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

Atlas read it once.

Then again.

”...Sanguis Stylus.”

His gaze shifted toward the crystal pen.

So the stylus had a name. Sanguis. Blood. The function became clearer the longer he looked. The book displayed his attributes, the stylus was the tool used to write into the blanks, and the ink source was blood. The locked fields meant there were limits or stages that could open later.

Atlas did not fully understand the relic, but he understood enough to identify the main difference.

This book did not give him a reward.

It did not tell him he had gained strength.

It did not bless him.

It wanted him to write.

Atlas reached for the Sanguis Stylus. The moment his fingers closed around it, a pulse moved into his hand. It was not pain. It felt closer to recognition. The red liquid inside the stylus shifted toward his grip, and the crystal surface became warm, as if the tool had accepted him as the one allowed to hold it.

Atlas looked back at the page.

The blank beside Strength waited.

What would happen if he wrote a number?

There was no explanation beyond the note. There was no voice, instruction, warning, or visible maximum except the locked fields after the blank. That meant the risk had to be judged by him.

Atlas did not write immediately.

If this relic accepted any number, then writing too high could be dangerous. A body had limits. Even if the book had healed his stomach, it might not safely rebuild him if he acted without thinking. The note also mentioned the current limit, which meant the Codex had stages even if he could not see the full rules yet.

If he forced too much into a body that had barely survived, the Codex could kill him.

Atlas’s mouth tightened.

The Royal Family had thrown him away because they believed commoner lives were cheap. He would not prove them right by dying from greed the moment he saw a chance.

He needed a test.

Small, controlled, and easy to observe.

Strength was the best option. If Strength changed, he would feel it in his hands, arms, legs, and body. If nothing happened, then the page might only be a display. If the change hurt too much, he could stop before touching the other attributes.

Atlas lifted the stylus.

The tip hovered above the blank beside Strength.

He chose a number.

Not ten or twenty.

Three.

He was not a trained Explorer or noble heir, but he was not helpless either. He had survived fights in the slums, carried weight, climbed walls, and run from men stronger than him. Three felt low enough to test but high enough to mean something.

Atlas pressed the stylus to the page.

The blood inside flowed to the tip and spread into a thin crimson line.

He wrote.

The moment the number was complete, the page absorbed it. The crimson mark sank beneath the surface, and the line changed.

Strength: 3 **[ LOCKED ]** **[ LOCKED ]**

For one second, nothing happened.

Then his body reacted.

Atlas dropped to one knee.

”Ghh—!”

His muscles tightened all at once. It did not feel like an injury. It felt like something was being pushed into his flesh and forcing it to match the number he had written. His arms burned first, then his shoulders, back, chest, and legs. The change followed the attribute clearly.

Strength.

His muscles compressed, pulled, and adjusted. The pain was short, but direct enough to make his teeth clench. Atlas held the stylus tightly and waited until the burning faded.

Several breaths passed.

When the pain ended, he remained on one knee with one hand pressed against the ground. His body was still weak from everything that had happened, but something had changed beneath the weakness. His hand felt steadier. His shoulders no longer shook as badly. His body did not feel like it would fall apart from standing.

Atlas slowly closed his fingers into a fist.

The difference was small.

But it was real.

He looked at his hand.

Then at the page.

”So it works.”

His voice was quiet.

There was no joy in it yet.

Only confirmation.

The Codex could change his body through blood-written attributes. That was not a normal relic. It was not even close.

Atlas stood again.

This time, his legs held better.

He looked at the remaining blanks.

Stamina.

Agility.

Spirit.

Each one meant a different survival path. Stamina could help him keep moving despite blood loss, exhaustion, and injury. Agility could help him avoid another instant attack from something faster than his eyes could follow. Spirit was more dangerous because it was the foundation of Revenants, Explorers, Guild elites, noble heirs, and everyone who stood above commoners. If he could write Spirit too, then the Codex was not only strengthening his body.

It was giving him access to power ordinary people were never allowed to reach properly.

Atlas’s mind sharpened.

The black monster was still somewhere above. The ruin entrance was either sealed, guarded, or too dangerous to approach. The old Scout and the Royal soldiers probably believed he was dead already. If Atlas wanted to leave this place alive, he needed more than luck. He needed enough power to move through the lower ruin, survive whatever else was inside, and eventually escape.

But every number required blood.

That was the price.

His blood was limited. If he spent too much now, he could weaken himself and die before reaching anything useful. That meant he needed a method. Small increases first, observe the effect, preserve enough blood to stay conscious, then find another source.

If monster blood worked too, then the ruin itself could become fuel.

That thought changed the situation.

Before, every monster inside the ruin was only danger.

Now, they could also be ink.

Atlas looked at the stylus. The blood inside had decreased slightly after writing Strength. Not much, but enough to prove the cost was real.

He turned the page.

A new page appeared.

**[ LOCKED ]**

Atlas did not touch it.

He only looked.

The lock gave no explanation.

He turned another page.

**[ LOCKED ]**

Then another.

**[ LOCKED ]**

Again.

Again.

Again.

Every page after the first was locked. Some locks were still. Others flickered faintly, as if something behind them existed but refused to open. One page distorted for half a second when his hand moved too close.

Chzz—!

A sharp static-like sound cut through the chamber.

Atlas pulled his hand back.

His fingers were not injured, but they tingled as if the page had rejected more than his touch.

He narrowed his eyes.

”So the first page is all I can use right now.”

That was useful information.

The book had more pages and more functions, but it would not give them to him for free. Maybe the condition was higher attributes. Maybe blood. Maybe survival. Maybe something else entirely. For now, only the profile and stats page mattered.

Atlas turned back to the first page.

**[ PROFILE ]**

**[ Name: Atlas Mariorett ]**

**[ STATS ]**

Strength: 3 **[ LOCKED ]** **[ LOCKED ]**

Stamina: _ **[ LOCKED ]** **[ LOCKED ]**

Agility: _ **[ LOCKED ]** **[ LOCKED ]**

Spirit: _ **[ LOCKED ]** **[ LOCKED ]**

The remaining blanks waited.

Atlas looked at them in order.

This was not excitement.

It was survival becoming a plan.

The world had already taught him the rule. People with power decided what happened to people without it. In Ormolio’s outer slums, a stronger man could take food. In the city, guards could beat commoners without fear. In the ruin, the Royal Family could throw him in first because his life had no shield around it.

If power was the only language this world respected, then Atlas needed to learn that language faster than anyone expected.

The Codex gave him a way.

But it came with rules.

Blood.

Limits.

Locked pages.

Unknown consequences.

Atlas understood the danger.

He also understood that doing nothing was worse.

He lifted the Sanguis Stylus again and looked at the blank beside Stamina.

The order mattered.

Strength had been the test. Stamina would decide how long he could keep moving. Agility would decide whether he could dodge and react. Spirit would come last because it was the least understood and likely the most dangerous to alter.

A dead man did not need Spirit, A slow man could be killed before using it.

But if he could endure and move, then he had time to learn.

Atlas placed the stylus near the Stamina blank.

His hand was steadier than before.

The chamber remained dark around him. The black monster still existed somewhere above. The Royals still waited outside the ruin, probably already counting him among the dead.

For the first time since being thrown into the Eternal Ruin, Atlas felt something other than pain.

Possibility.

The Sanguis Stylus touched the page.

And Atlas wrote again.