Inside the Cave of Obscenity
Volume 4 Chapter 9: The Limit of Evolution

"Everyone, please follow me!!"

The one who ran through the battlefield while shouting was Mariabelle, wearing a black dress and blue armor, with her black hair flowing in the air.

Without slowing down her running, she slashed away the tentacles that were extending and created a path for her companions to follow.

Mariabelle and her companions were inside the abandoned mine, past the entrance, which on the map could be called the halfway point.

The terrain was intricate, with countless branches, but there was no hesitation in their steps. The black-dressed hero ran toward the farthest point in the shortest distance.

According to Kara's plan last night, the main slime was located at the far end of the abandoned mine. She explained to Mariabelle that there was a large space there.

There were several reasons for that.

In the deepest part of the mine, it could buy time to intercept an intruder. It could also make the most of the slime's most annoying ability―― mimicry, to repeatedly surprise the intruder and tire them out until they reach the deepest part of the mine by giving them no time to rest.

Other than that, simply exploring in the dark for a long time was not desirable for humans, and it could take away their concentration.

――But this time, the situation was a little different.

Mariabelle and her group understood the threat of the slime and memorized the route in advance from the map, so they could head to the far end in the shortest distance and expose the slime's mimicry with the warrior priest's "Talisman of Light".

Normally, one hand would be holding a torch if the path was in total darkness, where no sunlight could reach, but the Warrior Priest's "Light of Exorcism" in their weapon would serve as a torch.

For the slime, which was immune to physical attacks, her companions armed themselves with mithril weapons that contained mana.

Exploring the abandoned mine with complete countermeasures would lead Mariabelle and the others to the slime, faster, accurately, and more precisely than any other party that had ever tried to capture this abandoned mine.

"Mariabelle-sama, look out!"

A young man from the tiger tribe with flames on his sword shouted.

The tentacles attacked from behind as Mariabelle ran too fast, leaving a gap between her and the others who were following her.

They were slimes that mimicked the rock walls, ground, and parts of the wood reinforcement.

Three tentacles attacked.

She was focused on the slimes in front of her that uncovered their mimicry in order to attack her, and as a result, her back was defenseless―― that was what it seemed like, but as though she had eyes in her back, Mariabelle immediately reacted and swung her arms to precisely cut off the tentacles that attacked her from behind.

Her father―― a hero from another world, who received a holy sword from the goddess, and when the blade glowed slightly, it vaporized the slime mucus and disintegrated it.

A natural enemy of monsters. The power of the hero.

The beastmen also have excellent senses, and if they were in good shape, they could even read the flow of the wind and predict the movements of their opponents.

However, Mariabelle's senses go way beyond that.

Prediction. Premonition.

It was a reaction that goes one step further than that, almost like predicting the future.

Having taken in tens of thousands of people, absorbed their will, and gained countless experiences, the slime's attack was a complete surprise, and even a skilled warrior could barely respond.

However, Mariabelle reacted to the surprise attack "easily" to those who were watching, fought back, and destroyed the slime with the least amount of movement.

(My body is in good shape.)

It had been quite some time since they entered the abandoned mine, but she was not even out of breath.

Her mind had been sharpened, and she almost feel as though her nerves have reached the tip of the holy sword. Her mind and body both know how to swing the sword even with a minimal amount of force.

(Because I slept well last night.)

Ever since her motherland, Fonteau, was destroyed by the slime, Mariabelle hadn't been able to sleep well even for a single day.

Naturally.

It wasn't just that she lost her home. Her own people were killed and attacked by the slimes, and they were forced to give birth to a monster child... The princess of the country was not strong enough to sleep under such circumstances.

It was not only her position as the princess of the country that supported her mind, which was as delicate as glass and likely to break at any moment but also her duty as the daughter of the hero.

It was because she believed that by destroying the monsters...... they could finally repay the lives that were lost.

However, with no experience in battle and inexperienced sword skills, it was difficult for Mariabelle to even destroy the monsters.

It was a situation that she immediately faced in reality and built up every time she was beaten down by Fornelis.

All of that deprived Mariabelle of a good night's sleep, and she didn't even realize it, but it was driving her insane.

But last night was different.

It was a deep sleep using a sleeping potion that no one else was willing to do.

It rested Mariabelle's mind and she slept really, really well.

Her body's movements were the most brilliant they have ever been, and she reacted to the slime attacks faster than the slime, thanks to her foresight, which was similar to her father's prediction of the future.

"Are you guys okay!?"

"We're fine! Don't worry about us, Mariabelle-sama, just concentrate on what's in front of you!"

Even the beastmen who were confident in their physical strength could barely follow her back.

Just a few months ago, she would have been nothing more than an amateur at fighting, but in the past few days, she had grown at a tremendous rate.

It was a noticeable change, and it was beginning to build a wall that separated between the hero―― those who received the blessings of the goddess and those who did not.

That was why the beastmen were desperately chasing after Mariabelle.

At the very least, they would protect her back. To stand behind her. For that purpose.

Don't let them slow her down. Don't get in her way. Desperately going after her.

"We're going to go all the way to the back! Let me know if you get tired!"

Mariabelle ran through the abandoned mine with her companions.

Desperately. With all their might.

In order to save her sister.

(Wait for me, sister.)

For the umpteenth time.

A few slimes got in the way, but their tentacles and poison did not reach Mariabelle, nor did they stain her.

She had already eliminated dozens of slimes, and she still had plenty of energy left.

She thought about running all the way to the back, but then she stopped.

(Kara-sama......)

Before they entered the abandoned mine, they made some arrangements.

No, it was a "promise" to protect Mariabelle, the hero.

In order to save her sister Meltia, the hero challenged the abandoned mine, and her companions would literally "risk their lives" to save her.

And to avoid total annihilation, the party was divided.

Now, Kara was not with them.

On the morning of that day, she told her that she had a few concerns and suggested that they split up the party to avoid annihilation.

Her companions wondered what she was talking about all of a sudden, but Mariabelle agreed.

Total annihilation.

Mariabelle, more than anyone else, understood that it was quite possible.

That was how powerful, mighty, and abnormal the slime had turned into.

That was why Mariabelle and the others split into two groups, and Kara disappeared. She used Mariabelle as a "decoy".

"We'll keep going. Are you all tired?"

"We're fine."

One of the warrior priests, breathing unevenly, opened his mouth.

There were no mages from Fonteau accompanying them. Since it was not suitable for magic in the closed space of the abandoned mine, if they were not careful, the mine could collapse and even get caught in it.

That was why all the mages were not in the first group, they were Kara's guards.

It was a wise decision, Mariabelle and her companions thought.

Kara was rational. She would sacrifice whatever it took to destroy the slimes and stay the course.

She gave Mariabelle a rest even if she had to drug her, use the hero as bait so she could move freely, and―― by placing mages away, it would divert the attention of the slimes that fed on mana away from Mariabelle.

Even so, she was trying to defeat the slimes.

It was terrifying, but it was an ability that Mariabelle didn't even have.

That was why Mariabelle trusted Kara and continued down the abandoned mine.

And then she reached the innermost part.

"......Ne, e-sama."

The place was hell.

The whole floor, not just the perimeter, was covered in slime mucus and pulsating.

The atmosphere was bizarre, as though the place had become a living thing.

Even her companions who had been making good progress up to that point stopped and cowered at the first sight, their mouths hanging open.

"What is this......"

After a while, the young man from the tiger tribe finally muttered just that.

In the middle of such a place, two naked bodies in their underwear were intertwined, surrounded by sunlight shining through the gap from the ceiling.

He didn't realize at first that it was Meltia and Fenelieka.

"Habu, haa, haa, hau."

"Nhh, chu...... hey, we endured."

The two of them were suspended in the air, their limbs restrained by the tentacles, but there was no "forced" atmosphere in their actions.

Meltia, who was both kind and strict, supported Mariabelle as an older sister and as a substitute for their mother.

The beautiful silver hair inherited from their mother, which she always took care of, hardened in just one night, covered in filthy mucus, and her ample limbs wrapped in pure white underwear emitted a foul smell...... The expression on her face was so depraved.

Desperately, and with all her heart, Meltia embraced Fenelieka in front of her, wrapped her arms around her neck, pressed her face to her, and kissed her.

The passionate kissing was so intense that even Mariabelle, who was far away, could hear the sound of saliva as her tongue entwined with it.

No, it was something that could be described by the word "sucking".

She was desperate.

Literally, if she didn't suck, she would die―― she would lose her life force and die. That was why Meltia desperately sucked the life force from the succubus Fenelieka, who in turn sucked the life force from the slime that was violating her, and continued to give it to Meltia all night long.

Even the succubus seemed to find it hard, and dark circles formed under her eyes, giving her a somewhat messy look.

The transformation in just one night left Mariabelle and the others speechless.

Fenelieka, in her passionate and flamboyant lingerie, was not so different from Meltia, but her expression was still intact, and she glanced sideways at Mariabelle and the others.

In the beginning, they suspected that the succubus Fenelieka had done something to Meltia, but the situation was just the opposite.

She kept the hero's sister alive and protected her for the night.

"Hey, nhh, nnh... Meltia, hey, your sister is here."

The slime had no intention of letting Meltia die.

She was a precious mother. A woman from the hero's bloodline.

But the aphrodisiac it gave her was too strong.

As a result of administering a large amount of aphrodisiac to make her impossible to resist, based on Mariabelle's fight with the humanoid, Meltia, who was not as strong as Mariabelle, could not endure.

The countless wills in the slime were driven by the desire to violate the "princess of the country" and went out of control.

The desires of thousands upon thousands of people prevail over the fundamental will of the Black Ooze, and they lay waste to Meltia and the beautiful succubus, Fenelieka, all night long.

Without thinking about their fatigue or limits.

They just violated and assaulted them, and yet Meltia and Fenelieka survived.

"――Youuu!!"

Mariabelle's enraged voice echoed through the abandoned mine, and without hesitation, she plunged into the sea of mucus that filled the floor.

The blue armor of the hero shone faintly, protecting her from the deadly poison of the slime.

When the poison proved ineffective, countless tentacles appeared from the floor and tried to block Mariabelle's path as she tried to run to Meltia.

"Don't get in my way!!"

With a fierce tone of voice that was not like the usual Mariabelle, she slashed several tentacles together with a sword slash that carried her emotions.

The light of the holy sword vaporized the tentacles, preventing them from regenerating.

But the sea of mucus understood that, and instead of regenerating the slashed tentacles, it created a series of new ones and tried to stop Mariabelle.

Even with a holy sword that could annihilate monsters, armor that could nullify poison, and a sense that could almost predict the future, Mariabelle was stopped from charging in the face of the overwhelming amount of mucus and seemed to be helpless when attacked by the endless tentacles.

……But she only stopped for a moment.

"Ahhhhh!!"

With a burst of energy, she swung the holy sword several times in an instant, and more than a dozen tentacles dissipated in the blink of an eye.

At the same time, more than a dozen tentacles were showing around Mariabelle, and she looked around to see if the situation was bad enough to be surrounded.

(Okay.)

She didn't ask for help from her companions.

They, too, were being attacked by a horde of slimes born from the mucus, who was trying to keep up with Mariabelle's assault so that they could not protect her.

That was why Mariabelle ran towards the wall, trying to change the current situation.

The idea was to eliminate the slime attacks, at least on one side. But of course, the wall was also covered with slime mucus, from which tentacles appeared.

"Fuu."

A flash.

However, the holy sword swung with such force that it almost left an afterimage, chopped the tentacles extending from the wall into tiny pieces, and neutralized them in an instant.

Next, Mariabelle thrust her holy sword at the wall.

"Please lend me your strength! Please, Fasalina-sama!"

Her desperate plea was not something that she was sure of.

But she was convinced.

Was it the memory left in her father's holy sword, or the knowledge engraved in the blood of the hero?

Either way, as the holy sword pierced the wall, it shone and dispelled the slime mucus that had adhered to the area, causing it to disappear in a circle.

The rock wall that appeared was natural, and there was no sign of the slime's mimicry.

"I can do this."

Mariabelle then stabbed the holy sword into the ground.

The mucus that covered the ground disappeared in a circular pattern, exposing the ground.

The slime couldn't stand it.

Its home, its nest, the sanctuary that it had taken the trouble to create, disappeared just by being pierced by the holy sword. It was becoming fragile.

It tried to cover what was lost with new mucus, but the hero's daughter's action was much faster than that, just sticking the holy sword in.

The slime had a mass that humanity couldn't even imagine, but there was a limit to how much it could use at a time.

It was something that would not change no matter how strong they become or how much they grow.

It was the limit of the "species" called slime.

That was why countless Black Oozes push the limits by clumping together and sharing their knowledge with other slimes.

However, the "nucleus" of the slime that sank into the sea of mucus was swallowed by the light of the holy sword and disappeared.

Each time it was attacked, the amount of mucus it could use decreased.

It was not a matter of compatibility or incompatibility. There was an overwhelming difference in power and the fact that Mariabelle, the daughter of the hero, was inexperienced and still had room to grow.

It was not just that she had the ability to see the future, but she also had the ability to react to it.

That was why the hero, who had never even held a sword before, let alone fought, defeated the Demon King in just a few years and saved the world.

The slime desperately fought back against the unusual growth speed and attacking ability.

Countless tentacles attacked from all directions, from the ground, from the walls, from the ceiling, and Mariabelle calmly and carefully crushed them one by one.

Even so, the slime still had some mucus left to use, even if it was slowly being weakened.

Either Mariabelle would get tired first, or the slime, which was massive enough to swallow the entire abandoned mine, would disappear......

But it was the slime who threw in the towel.

"Haah, haah... it came out."

The wall on the other side, at the center where Meltia was hanging.

The humanoid slime emerged from the transparent wall.

On the other side of the wall which was slightly transparent, a food and livestock storage where the slime's spoils―― the succubus and village girls captured near the mine were kept.

What was being done there...... It was horrifying for Mariabelle, who was also a woman, to even think about.

"――――"

The humanoid swung its right arm.

The mucus sword that blocked even the light from the holy sword, as demonstrated when they fought outside the abandoned mine.

"Perhaps that arm is covered in mana."

It was something that Kara discussed before they entered the abandoned mine.

"It is said that the light from the hero's holy sword can annihilate monsters and take away the Demon King's ability to regenerate. I'm sure the slime is no exception. The ability to regenerate is the slime's greatest weapon."

No matter how much was chipped off, it quickly regenerated and started to fight back.

That was the strongest ability of the shapeless slime.

However, the hero's holy sword sealed its regenerative ability. Annihilation, in the best way possible.

"In other words, the light from the holy sword can only extinguish it if it is a monster."

That was why.

"I think that the humanoid covered its arm with mana and its arm was recognized by the holy sword as something different from the mucus of the monster......"

She didn't experiment with it, so she had little information on it.

Kara said.

The answer she derived from the little information she had was correct.

By covering its arm with mana, the humanoid made the holy sword recognize that it was a different substance than the "monster cells" and turned its sharp blade resembling the holy sword.

However, it was only the right arm.

In order to prevent the light from the holy sword, the humanoid must use all of its available mana on a part of its body, and it could not use it for attack or assistance.

The amount of mana available to a mere slime was limited, even though it had taken in the blood of the hero.

It had a limit.

On this imperfect, mutant that had only taken in a small amount of hero's blood.

"I will defeat you and save onee-sama!!"

Mariabelle declared, and ran off, dragging the holy sword on the ground with its tip.

The tip of the sword eliminated the mucus covering the ground, and that alone was enough to control the tentacles that were trying to assist the humanoid.

It was a sight that seemed to gouge the ground.

Where she ran, the mucus disappeared, and it looked as though a path had been created.

As she ran to the humanoid, Mariabelle used her momentum to slash up the holy sword.

At the same time, the humanoid parried the holy sword with the sword on its right arm, which had been transformed from its shoulder to the tip.

The fierce light from the holy sword clashed with the pale magic light from the sword.

Different from the clash of iron against iron, there was a fierce spark as divine power and mana collided.

"Kuh!"

Fast, strong, and heavy.

With her mana circulating throughout her body, Mariabelle had also improved her physical abilities considerably, but the humanoid was even more so.

Countless warriors, adventurers, mercenaries, and knights―― their knowledge and experience moved the humanoid's soft body to point their sword at Mariabelle with their best and most effective movements.

However, Mariabelle understood and anticipated where and how the attack would come and fought off the humanoid's attack.

Both swords became so fast that they gave off afterimages to those who were watching, but none of them were fatal.

Mariabelle aimed for the place that was not covered by mana, but the humanoid knew its weakness and protected it.

While doing so, tentacles appeared around her and attacked her from her blind spot.

――Mariabelle of yesterday would have been defeated by it.

Until yesterday, she had a hard time fighting the humanoid.

However, after a good night's rest, Mariabelle was able to fight the humanoid with movements that were completely different from yesterday, accurately slashing away the tentacles that attacked her, and running and jumping in all directions in the mucus-covered space.

Sometimes she even had the luxury of slicing through tentacles that weren't meant for her to help her companions who were being attacked by slimes.

(Maybe I'm getting used to it......)

It was not carelessness.

She had a wide field of vision. She was feeling relaxed.

The anger of having her sister violated and the luxury of being able to calmly observe the enemy.

It made Mariabelle's movements even more accurate, precise, and daring.

She dodged the tentacles then slashed them with effortless force, and attacked the humanoid slime with the shortest and smallest movements.

The tentacles were absolutely impossible to ignore because of their powerful paralyzing poison, but it was not the case for Mariabelle, who could nullify the poison by wearing the armor of the hero.

The paralyzing poison that had been the slime's special attack until this day was nothing more than a liquid for the hero.

Her movements were as though she was dancing, and she attacked with a sword dance that no knight or swordsman in the humanoid had ever seen before.

"――――"

Its right arm alone could not keep up.

Gradually, its body was being whittled down. Its shoulders. Its fingertips, Its head, Its feet.

Little by little, inch by inch―― it was being sliced.

For the first time in its life, the humanoid was confused.

Until yesterday, it had indeed been overwhelming her.

Even though it had lost, it had learned from yesterday's experience and it was supposed to be a battle it could not lose.

However, in just one night, Mariabelle had grown to a higher level, and her prediction of the future had become more accurate, and she was cornering the humanoid with an overwhelming difference in ability.

In this situation, the tentacles that were attacking her from her blind spot were meaningless.

In fact, the tentacles were even used to make them fight each other.

The humanoid couldn't understand it.

What awakened the hero's daughter and made her grow―― or rather, evolve to this level?

If it was the anger over tormenting her sister, a being who only imitated others could not understand.

"――――"

But the humanoid couldn't understand and was bewildered, it was upset and slowed down its movements in a hapless manner.

The swing from the sword and the movement of the tentacles visibly slowed down.

It was no different to the untrained eye, but to Mariabelle it was an absolute gap.

The move seemed like a trap, but Mariabelle aimed with absolute confidence.

"With this!!"

Not missing its agitation, Mariabelle slashed the humanoid's right arm off its shoulder.

The sword on its right arm, which was wrapped in a pale light, flew through the air, but the humanoid was unable to regenerate the missing part.

The light from the holy sword interfered with its regeneration.

"The finishing blow!!"

Mariabelle tried to cut off its head, but the humanoid was quicker than that and countless spears appeared from its body.

Shoulders, torso, legs, and back―― more than thirty sharp spears were shot out from its entire body in an instant in all directions.

"Kuh!?"

Mariabelle jumped back and avoided it, then the humanoid summoned tentacles to the surrounding area to restrain the hero.

......Only one.

The slime that swallowed thousands or tens of thousands of lives was overwhelmed by just one human, the hero.

It should be a nightmarish scene, but the humanoid had no fear.

Its role had already been completed.

Once it had absorbed one of the archbishops in the holy kingdom of Lishlua and understood the next course of action for Meltia and the others, determine their objective, and it was done.

Grow endlessly. Use magic.

Comparable to that, it was not afraid of death.

Literally, the slimes were a group, all sharing the same knowledge.

"Then this would be――."

Mariabelle lowered her hips slightly, held the holy sword in both hands, and held it up.

There were many gaps.

The surrounding mucus created a large number of tentacles and tried to attack, but the light flashed from the blade of the holy sword earlier than that, illuminating the entire space at the innermost part.

The mucus walls and floor, illuminated by the strong light, emitted white smoke and evaporated, even though they were not directly touched.

The humanoid quickly created a thick wall of mucus in front of itself.

It intended to use it to block the light from the holy sword.

It was indeed thick. It was so thick that it looked like pitch black darkness when one looked at it from the direction where Mariabelle was.

As expected, it might not be possible to penetrate such a thick wall―― but Mariabelle believed in it.

"――You have so many openings, you son of a bitch."

Foul-mouthed words came from above.

The ceiling of the abandoned mine with a gap. In the sunlight, there was a small shadow.

It was Kara and the others, who had parted ways at the entrance to the abandoned mine.

Yesterday, Kara had seen the humanoid fleeing in a different direction from the entrance to the abandoned mine, and she thought there might be another way in and out, so she set out from the outside of the mine to the far end.

What she arrived at was a gap in the ceiling.

It was no place for a person to enter. It was too high, and if one of them were to fall from it, they would be seriously injured.

However, it was large enough to "throw things" into.

"This is payback for the research tower."

She then took out a test tube from her pocket and threw it at the humanoid.

The humanoid was not stupid.

It didn't even know what the liquid in the test tube was, but it was something that a woman who dabbled in the human race's taboo by studying the power of a goddess would throw.

Judging it to be dangerous, it gently caught the test tube with its tentacles so as not to break it.

"Now!"

"Yes!"

But Kara had read that far.

As soon as the tentacle caught the test tube, the mages who accompanied her destroyed the test tube with wind magic.

The shockwave scattered the liquid inside to the surrounding area, and the humanoid was no exception.

Because it had been focusing on Mariabelle, its reaction was delayed, and the humanoid and the surrounding mucus were bathed with unidentifiable liquid.

The effect was immediate.

"――――"

For the first time, the sea of mucus and the humanoid began to rampage like mad.

The tentacles reamed haphazardly across the empty space, the walls that had been trying to block Mariabelle's attack collapsed out of shape, and the floor and walls rippled violently like a huge wave in a storm.

The humanoid could no longer hold its shape and quickly collapsed to half its original size, losing its head and gradually melting into a sea of mucus.

"This is "Valhari's Poison"......"

The mage who blew away the test tube with wind magic muttered.

A small amount of liquid was inside the test tube, which was only about the thickness of an index finger.

With that, the slimes flailed, struggled, and crumbled.

"Not yet, Mariabelle-sama! It only worked on the mucus―― destroy the "nucleus"!!"

"――Yes!!"

Mariabelle didn't hesitate. She was not the one who should have such feelings.

However, those who have lost their lives to the slimes and those who have been violated...... she swung the holy swords in response.

The holy light that defeated even the demon king who created infinite monsters filled the area at the innermost part of the abandoned mine―― extinguishing every drop of the sea of mucus that filled the place.