Bloodbound Codex: I Grow Stronger in Secret

Darkness swallowed the Royal Revenants the moment they crossed the entrance of the Eternal Ruin.

The massive doors behind them rumbled shut, and the sound spread through the structure like an old mechanism waking after centuries of stillness. Once the entrance closed, the outside world disappeared completely.

Only darkness remained.

The Revenants reacted immediately.

Spirit Energy moved through their bodies, sharpening their senses and reinforcing their perception. These were not ordinary Explorers who panicked when vision failed. Every person in the formation had entered dangerous ruins before, fought spiritual monsters, and survived places where one mistake meant death.

Even then, the darkness did not retreat much.

One Revenant reached toward the relic hanging from his waist and twisted it.

Click.

A pale blue glow spread outward from the relic-lantern, revealing part of the black stone corridor ahead.

Then another lantern activated.

Then another.

Light spread through the group one by one, pushing back enough darkness for the formation to move, but not enough to expose the full corridor. The shadows inside the Eternal Ruin were too dense. Relic light worked, but only barely.

Velmira Ashenworth walked at the front.

Her crimson eyes moved across the corridor walls, studying the ancient runes carved into the black stone. Unlike the runes outside, the ones within the ruin glowed faintly, pulsing at slow intervals as if reacting to the Spirit Energy signatures of the Revenants.

One Revenant broke the silence.

”...This place feels eerie.”

His voice was lower than before despite his large frame.

Another nodded.

”It doesn’t resemble any ruin I’ve entered before.”

A woman near the middle of the formation let out a dry laugh.

”Of course it doesn’t. This place has been sealed for nearly a thousand years.”

The first man frowned while keeping one hand near the spear on his back.

”No, that’s not what I mean.”

His gaze moved across the corridor.

”Ordinary ruins have structure, spirit flow, patterns, even unstable ones follow some kind of internal logic.”

He paused.

”But this place feels like the ruin is...watching us.”

No one mocked him.

That mattered.

Everyone present felt the same thing. The pressure in the corridor was not only caused by old Spirit Energy or sealed space. The floor vibrated faintly whenever the runes pulsed. The air resisted their presence. Even their enhanced senses could not fully map the darkness ahead.

Another Revenant muttered quietly.

”This ruin almost feels...”

He hesitated.

”...alive...?”

The relic-lanterns flickered.

Several hands moved to weapons at once.

The lights stabilized a moment later, but no one relaxed.

Velmira finally spoke without slowing her pace.

”Maintain formation.”

Her calm voice carried through the corridor.

”And do not separate under any circumstance.”

The Revenants adjusted immediately.

Frontline moved closer, Rear guards moved wider.

Long-range fighters protected between them.

No wasted movement.

These were the Empire’s strongest hunters, and discipline was why they had survived this long. Confidence was useful, but formation kept people alive inside a place where unknown rules could kill faster than monsters.

Minutes passed as they advanced.

Their armored footsteps echoed across the black stone corridor, and the runes continued pulsing faintly around them.

Then one Revenant stopped.

”...Blood.”

The formation halted at once.

The relic-lanterns shifted forward.

Dark stains covered sections of the floor ahead. Some had dried into the stone. Others marked broken areas where the ground had been struck with heavy force. Shattered fragments of black rock lay scattered nearby, and several cracks spread across the corridor walls.

Velmira’s eyes sharpened slightly.

”Move carefully.”

The group advanced again.

The deeper they walked, the more signs of conflict appeared.

Cracked walls, collapsed stone, impact marks driven into the floor.

A section of wall had caved inward as if something had been smashed against it with tremendous force.

One Revenant crouched beside a crater and frowned.

”These marks...”

His expression changed slightly.

”...something powerful fought here.”

Another touched the broken stone near the wall.

”The impact came from the side. Something was thrown through this area.”

The conclusion was simple.

A fight had happened before they entered and it had not been a small fight.

Then the smell reached them - Rotting flesh.

Several Revenants turned toward the darkness ahead.

The lantern light slowly revealed a massive body collapsed against the floor.

A corpse.

A Hybrid Muxical lay motionless before them, four tails spread lifelessly behind its body. Dried black stains marked the ground around it, but what made the Revenants stop was not the species.

It was the condition.

The body looked completely drained.

Its skin had tightened against the bone. Its eyes were sunken. Its flesh had shriveled unnaturally, and there was no fresh blood left in the corpse.

One Revenant’s eyes widened slightly.

”...A Hybrid Muxical?”

Another narrowed his gaze.

”And not a weak one.”

Even dead, the creature still carried faint spiritual pressure. It was a mature B-Rank spiritual monster. A creature like this could slaughter ordinary hunter squads alone, and careless low-ranked Explorers would not even escape its first charge.

Yet it lay dead, Bloodless.

A woman among the Revenants spoke first.

”...Did another monster kill it?”

”Impossible,” another replied immediately.

”There are no claw wounds.”

”Then what drained its blood?”

No one answered.

Because there was no normal answer.

The silver-eyed Revenant near the back stepped forward.

Unlike the others, he did not focus only on the corpse. His eyes moved across the area first: the cracked wall, the crater, the shattered floor beneath the creature, then finally the neck and spinal area.

His gaze narrowed.

”...Interesting.”

Velmira glanced toward him.

”What did you notice, Mark?”

Mark crouched beside the corpse calmly.

”The spinal area.”

Several Revenants focused on him.

Mark pointed toward the back of the Hybrid Muxical’s neck.

”It was broken.”

One Revenant frowned.

”So?”

Mark rose slowly.

”So it was not torn apart.”

His silver eyes sharpened slightly.

”It died from blunt force.”

Silence spread through the corridor.

Several Revenants stepped closer and examined the corpse properly. Once they looked past the drained state, the cause of death became obvious. The spinal structure had collapsed inward. The skull had been driven downward with enough force to snap the connection between head and body.

Mark spoke again.

”Something physically killed this creature.”

The atmosphere changed immediately.

That detail mattered more than the corpse itself.

A Hybrid Muxical had high durability for a B-Rank spiritual monster. Killing one was not impossible for S-Rank Revenants, but crushing its spine with blunt force in a single exchange required far more than ordinary strength. It meant either another powerful monster had struck it, or someone inside the ruin had done so barehanded or with a heavy blunt weapon.

Velmira stepped closer.

She crouched beside the corpse and placed one armored hand lightly near the shattered spinal area. Her crimson eyes observed the damage for several seconds.

Then she spoke.

”...Single strike.”

The corridor became quieter.

Velmira stood.

”This creature died from one impact.”

No one dismissed those words.

Coming from Velmira, it was a direct assessment.

One Revenant muttered.

”...What exactly happened in here?”

No one answered.

Then the ruin reacted.

VRRRRMMMMM.

The glowing runes across the walls pulsed violently.

The entire corridor trembled beneath their feet.

Weapons came out instantly.

Spirit Energy erupted from the Revenants’ bodies as they shifted into combat formation.

”Formation!”

The group moved without delay.

Frontline weapons raised.

Rear guard locked position.

Long-range Revenants prepared their relic bows.

Velmira slowly lifted her gaze toward the darkness ahead.

A growl echoed.

”Grrrrrr...”

Then another.

Then several more.

The Revenants’ expressions hardened.

They recognized the sound.

Hybrid Muxicals.

Multiple.

The relic-lanterns flickered violently.

Pairs of crimson eyes opened in the darkness ahead.

One pair.

Then another.

Then dozens more.

They watched from beyond the lantern light, spread across the corridor like predators waiting for a signal.

Then the growls stopped.

The Hybrid Muxicals retreated slightly into the shadows.

Not from fear of the Revenants.

To make way.

Heavy footsteps echoed from deeper inside the corridor.

THUD.

THUD.

THUD.

The creature that emerged was larger than the others.

It resembled a wolf standing on two legs, with massive muscles beneath dark fur and seven enormous tails moving slowly behind its body. Its claws scraped lightly against the black stone floor, and its crimson eyes did not carry simple animal hunger.

They carried intelligence.

One Revenant unconsciously took half a step back.

”...An Ulgroth.”

Another’s voice lowered.

”S-Rank...”

The atmosphere became heavier at once.

Hybrid Muxicals were dangerous predators.

An Ulgroth was an evolved spiritual monster.

It had surpassed ordinary instinct and entered true spiritual evolution. A creature like this could slaughter towns if left unchecked, and even trained Revenants could die if they underestimated it.

Velmira remained calm.

Her crimson eyes observed the towering creature for a moment.

Then she spoke.

”Mark.”

The silver-eyed Revenant looked toward her immediately.

”Come forward.”

The surrounding Revenants glanced between them.

Velmira’s voice remained composed.

”I know you can defeat it easily...”

Her gaze sharpened slightly.

”...but consider this a form of training.”

Mark’s eyes narrowed subtly.

”Training?”

Velmira nodded faintly.

”Use only your physical techniques against it.”

The Ulgroth released a low growl while staring directly at them.

Velmira continued.

”Then perhaps...”

A dangerous glint appeared in her crimson eyes.

”...you might finally learn something useful.”

For the first time, Mark’s expression shifted slightly.

Only slightly.

But enough.

His thoughts moved quickly.

’Does she know?’

A faint chill passed through him.

’No... impossible.’

His silver eyes narrowed toward Velmira’s back.

’She is only commanding me.’

Despite that, Mark stepped forward calmly.

His black cloak swayed as he moved ahead of the other Revenants and stopped before the towering Ulgroth.

Then he spoke.

”I will follow your command thoroughly, Commander Velmira.”

His tone remained respectful.

Focused.

Yet behind his silver eyes, something cold flickered briefly while he stared at the monster ahead.