Investing in My Harem in the Apocalypse Makes Me Stronger

[Black Menagerie (Primordial-rank) — A mysterious inner world exists within your body, containing ancient beasts sealed inside it. As you advance through the Echelons, more beasts and abilities will be unlocked. Your first beast is the Primordial Chaos Dragon.]

[Piercing Momentum (S-rank) — Greatly increases the speed, force, and penetrating power of anything you throw. The better your throwing technique and momentum, the stronger the attack becomes.]

[Ruin Dragon Force — Allows you to borrow the Primordial Chaos Dragon’s Ruin energy. You can circulate it through your body to greatly increase your physical strength, or coat weapons with it to amplify their sharpness, force, and destructive power. Weapons covered in Ruin Dragon Force can weaken armor, corrode defenses, suppress regeneration, and continue destroying the target from within after piercing its body.]

Cain read the first description twice.

A mysterious world existed inside his body.

An entire inner world containing ancient beasts.

Cain recalled the endless darkness and the colossal golden eye he had seen while unconscious.

A chill ran down his back.

”That thing was inside me?”

He did not know how large the creature had been, as he had only seen one eye and it was as if he felt as tiny as dust in front of it.

Cain looked at the line beneath the Talent description.

Primordial Chaos Dragon.

His uneasiness lasted only a few seconds before another thought entered his mind.

’Does that mean I’ll eventually be able to summon it?’

The image of himself standing on top of a colossal black dragon immediately appeared inside his head.

He would fly over ruined cities with his arms crossed while terrified enemies looked up from below. Naturally, there would also be several beautiful women riding behind him.

Cain’s lips curved upward.

’A Dragon Knight flying through the sky and yoinking beauties everywhere...’

”That doesn’t sound bad.”

He moved to the next Talent.

Piercing Momentum was clearly related to his javelin experience.

Cain had trained in the sport since he was young and had even won a gold medal at an international competition. Throwing technique had been carved into his muscles through years of repetition.

Now, an S-rank Talent would amplify that ability beyond normal human limits.

If he found a proper javelin, spear, or even a sharpened metal rod, its destructive power should be terrifying.

However, Ruin Dragon Force interested him even more.

Increasing his physical power was already valuable, but the ability to amplify sharpness and destructive power as well as weaken, suppress regeneration, and destroy whatever his weapon struck sounded ridiculous.

”Holy fuck...”

Cain looked down at the bloody mop in his hand.

A broken piece of wood had been enough to kill the first zombie. What would happen if he coated a real weapon with Ruin energy?

Before he could experiment, the bathroom door suddenly flew open.

Bang!

A young man stumbled inside.

His face was pale, and he held his left arm against his chest. Blood seeped between his fingers.

”Cain!” The young man nearly slipped on the wet floor as he ran toward him.

”Help me!”

Cain recognized him immediately.

”Franz?”

Franz lived in one of the rooms near the stairwell. They were not particularly close, but they had spoken several times before.

A zombie rushed through the doorway behind him.

Cain had no time to think as he instinctively activated his (Ruin Dragon Force) skill.

A deep pulse erupted from somewhere inside his chest.

Dark gray energy surged through his veins.

Cain felt an enormous force pour into his muscles. The broken mop in his hand became covered by a faint layer of dark energy that caused the wooden surface to crack and decay.

The approaching zombie lunged.

Cain stepped forward and thrust.

The mop pierced through its eye.

Unlike before, there was almost no resistance.

The Ruin energy coating the weapon weakened the zombie’s skull upon contact, allowing the jagged wood to pass through as easily as wet soil.

[Ding! You have killed a Level 2 Zombie.]

Cain yanked the mop free and turned toward the doorway with a serious expression.

Nothing else followed.

He remained alert for several seconds before lowering the weapon.

”That was easier than—”

A low growl came from behind him.

Cain’s skin prickled. He instinctively swung the mop backward without turning around.

Crack!

The wooden shaft struck Franz across the face.

Franz had already transformed.

His eyes had become cloudy, and black veins spread from the bleeding wound on his arm toward his neck. His mouth opened wide as he lunged for Cain’s shoulder.

The mop snapped in half upon impact, but the force threw Franz sideways.

He crashed against one of the sinks.

”Shit!”

Cain finally understood.

Franz had been bitten before entering the bathroom.

The blood covering his arm was not from a simple injury.

Cain rushed forward before the newly transformed zombie could recover.

He gripped the shorter half of the broken mop with both hands and drove it into the side of Franz’s head.

[Ding! You have killed a Level 2 Zombie.]

Cain immediately pulled the weapon free and stepped back.

”Fuck...”

He breathed heavily while staring at Franz’s corpse.

”That was dangerous.”

If Ruin Dragon Force had not increased his physical abilities and sharpened his movements, Franz might have reached him.

Cain had assumed that the infection required at least a few seconds after death.

Franz had transformed while still standing.

That meant every bitten person was a threat, regardless of whether they appeared conscious.

Cain memorized that fact.

Trusting the wrong person for even a moment could kill him.

A faint white light suddenly appeared above Franz’s corpse.

The light gathered into a small sphere approximately ten centimeters wide before falling onto Franz’s chest.

Cain waited for a moment, but nothing happened.

He crouched and cautiously picked it up.

The orb felt smooth and strangely warm.

[White Orb: Contains one random Unranked item.]

”How do I use it?” Cain turned the orb over in his hand.

No instructions appeared.

He held the orb in front of him.

”Use.”

Nothing happened.

”Open.”

Still nothing.

”Equip?”

The orb remained unchanged.

”Come out?”

Silence.

Cain’s forehead twitched.

He shook the orb beside his ear, but there was no sound from within.

Cain tried twisting it, pulling it apart, and pressing its surface with his thumb.

Nothing worked.

His patience quickly disappeared.

”Fine.”

He tightened his grip.

”If you don’t want to open nicely, I’ll smash you against the wall.”

The orb cracked beneath his fingers.

A soft white light flashed.

Cain instinctively loosened his grip.

The broken orb disappeared, and a black dagger materialized in his hand.

Its blade was a bit more than 20 centimeters long. The edge was sharp, while the handle was wrapped in dark leather that fit comfortably inside his palm.

[Unranked Dagger (Unranked) — A simple dagger possessing greater durability and sharpness than an ordinary military-grade knife.]

”Not bad.”

Cain examined the blade with a satisfied smile.

The weapon was far better than a blood-covered piece of broken wood.

He released the makeshift spear and let it fall beside Franz’s corpse.

Cain then deactivated Ruin Dragon Force.

The dark energy inside his veins immediately receded.

The immense strength filling his muscles vanished along with it, leaving his body slightly stiff and unusually heavy.

Cain rolled his shoulders and stretched his arms.

”It drains my mana quite quickly.”

He hadn’t used the ability for that long, but he could already feel that a noticeable portion of his Mana had disappeared.

Ruin Dragon Force was powerful, yet he could not leave it active carelessly.

Cain opened his status again.

[Cain]

[Level: 1]

[Race: Human]

[Talents: Black Menagerie (Primordial), Piercing Momentum (S-rank)]

[Beast: Primordial Chaos Dragon]

[Element: Ruin]

[Skills: Ruin Dragon Force]

[Free Stat Points: 3]

[Stats]: Strength: 19 / Agility: 15 / Physique: 17 / Sense: 14 / Mana: 170 / Magic: 68

Cain looked at the available points.

He did not hesitate for long.

Even though speed, endurance, and perception were all important, his current enemies were corpses that did not feel pain. Unless he destroyed their heads, they would continue attacking.

Strength would make every stab, kick, and throw more lethal.

That was why he decided to put all three points to it.

A warm current spread throughout his body.

His muscles tightened slightly beneath his skin. His bones felt denser, and the dagger in his hand suddenly seemed lighter than before.

[Strength: 22]

Cain clenched his fist, a grin appeared on his face.

He had spent years training to improve his body. Normally, even a small increase in strength required months of discipline, strict dieting, and carefully planned exercise.

Now, killing a single zombie and assigning three points had noticeably strengthened him within seconds.

Cain liked that feeling. In fact, he liked it very much.

”If I continue leveling...” His eyes shone faintly.

Then another scream echoed from the hallway, reminding him what kind of situation he was in.

Cain put the dagger through his belt and took out his phone.

There were several unread messages on the lock screen, but the signal icon had disappeared.

He tried calling Ron, but the call failed immediately.

He then tried sending several messages to his family, but they also didn’t go through.

’I hope they’re going to be okay.’ Cain thought of his family, especially his cute little sister.

”Please hang in there for a bit, I’ll be there soon.” He murmured to himself with a weak voice.

Cain then placed the phone in his pocket and cursed in his heart as the world had apparently decided that zombies were not troublesome enough.

He approached the bathroom entrance and looked into the hallway.

It was quieter than before.

That was not necessarily a good sign.

Most of the screaming had stopped, and several corpses now lay across the floor. A few zombies wandered aimlessly between the rooms, occasionally striking locked doors whenever they heard movement inside.

Cain’s room was on the second floor.

The bathroom and one of the stairwells were located near the end of the first-floor corridor, which meant he could reach the stairs without crossing the entire building.

Cain tightened his grip on the dagger.

He stepped outside and the smell of blood struck him first.

And something foul that reminded him of rotten meat left beneath the sun.

Cain forced himself to ignore it as he moved toward the stairwell, keeping close to the wall.

One zombie stood several meters away with its back turned. Cain avoided it rather than wasting time and continued upstairs.

The second-floor corridor was also stained with blood.

Most of the room doors were closed, but several had been left open. Cain heard muffled sobbing from somewhere nearby, along with the sound of furniture being dragged across a floor.

Two zombies wandered between him and his room.

One was an overweight student wearing nothing but shorts. The other was a thin young man with half his throat missing.

Cain approached quietly.

Unfortunately, the overweight zombie noticed him first.

It groaned and charged.

Cain waited until it entered striking distance before stepping aside.

His left hand caught the creature’s shoulder, redirecting its momentum. At the same time, his right hand drove the dagger through its temple.

[Ding! You have killed a Level 2 Zombie.]

Cain pushed the corpse away and immediately faced the second one.

The thin zombie opened its mouth and rushed him.

Cain kicked its knee.

The joint bent in the wrong direction, causing it to collapse forward.

Before it could crawl closer, Cain stabbed downward through the top of its skull.

[Ding! You have killed a Level 2 Zombie.]

Cain wiped the dagger against the dead student’s shirt.

Compared to his first kill, his hands barely trembled this time.

He did not know whether that was a good thing.

Cain finally reached his room and grabbed the handle, but when he wanted to open it, it was locked.

He could hear a struggle inside.

Something struck the floor, followed by a familiar voice shouting several curses in rapid succession.

Cain stepped back, he gathered strength into his right leg and kicked beside the lock.

Bang!

The door flew open.

Inside the room, a young man lay on his back near Cain’s bed.

He had short black hair, a lean athletic body, and a panicked expression. Both hands gripped the shaft of a javelin, which he had pressed horizontally against a zombie’s throat.

The zombie clawed at his face while snapping its teeth.

”Cain!”

The young man’s eyes widened.

”Help me get rid of this fucker!”

Cain released a breath he had not realized he was holding when he saw that his roommate was alive.