Villain: Ultimate Mutation System in the Alternate World

He stepped into the large hole, carefully navigating through the rough, uneven edges.

As he descended deeper into the tunnel, he noticed that it sloped downward at a steep angle.

He estimated that he had already descended at least 50 meters downward since entering the tunnel, a long distance considering he was already underground.

The air inside was damp and musty, carrying a faint odor of soil. Paths twisted and turned, narrowing at some points and widening at others.

It was clear this was not a man-made structure, but rather something formed naturally or by the creatures that inhabited it.

The further he went, the more he noticed signs of the rats: gnawed bones, shredded scraps of cloth, and deep claw marks etched into the walls.

After walking for another 15 minutes he found a cavern from which dozens of tunnels branched out in all directions.

'This place is bigger than I thought. Don't tell me this is a huge monster nest link together?' he pondered, hesitating whether to proceed further.

It wasn't that he was afraid of being overwhelmed by a bunch of rats.

With his durability and skills, he doubted they could even harm him, even if he let them bite him intentionally.

However, what concerned him more was the amount of time he would waste checking all these tunnels.

He weighed the potential benefits against the risks, considering the pros and cons of his exploration.

'I've been gone for months now, so adding a few more days won't make a difference,' he reasoned.

It was better to explore this place and search for something of value.

For all he knew, this place held something that could help him reach the status of a Demon Lord.

Even after all his improvements and upgrades, when Reign inquired about his power level from the system, he was still classified as a Peak Upper Level.

This showed the huge gap between his current level and the next rank.

'Now let's see….' his voice trailed off as he began feeling along each tunnel entrance.

He was searching for a sign, or even a slight gut feeling, to guide him on which path to take.

With how high his attributes were, he felt that having a knack for finding the right path should come naturally.

As he felt each tunnel entrance, he focus his mind and let his instincts guide him. He locked on the subtle shifts in energy, the faintest whispers of the air, and the vibrations under his foot.

Finally, one tunnel gave him a sense of curiosity and unease, a combination that often led to something worthwhile.

'Let's see where this goes,' he muttered, stepping into the chosen tunnel.

Experience more on m,vle,mp _yr.

The air grew cooler as he walked, and for some reason he felt like there was something in the air.

'Could it be?' Reign paused, then he increased his Viral Slash from level 10 to 20 and began absorbing any virus that it could detect.

Immediately, the air around him was sucked in as the ability took effect.

He sensed a surge as the viruses were drawn towards him, swirling into his body like a whirlwind before settling into his special viral gland.

[System : New Virus Created ]

=====

Lethality : 20%

Incubation periods : 20 minutes

Transmission routes : Close Contact

Virulence : Medium.

Symptoms:

-Nausea

-Vomiting

-Migraine

-Fever

-Rashes

=====

'This virus will work wonders against humans, but against strong opponents, I doubt it could do much,'

Stronger individuals would have superhuman immune systems to kill the virus right away in their bodies, and he doubted it would work against demons who where basically walking virus themselves.

Regardless, having this meant he could simulate his own pandemic and kill a lot of humans if he needed to.

Reign was tempted as he considered the possibilities. He could unleash this virus in human cities, creating chaos and weakening his soon to be food before they even knew what hit them.

Of course, he wasn't planning to use it right away, but having this in his arsenal gave him more options. The virus was a tool, a means to an end, and he would deploy it when the time was right.

Reign continued his exploration, moving steadily through the tunnel.

He sensed traces of the virus ahead, but it was the same strain he had already absorbed, weaker and less potent. It wouldn't add much to the virus's lethality.

***

After about 20 minutes of travel, he finally reached the end of the tunnel, where it opened into a vast cavern.

The ceiling was high, and the area was filled with the remnants of the rats' activities.

In the center of the room was a large, nest made of a tangled mess of debris, fur, and bones.

'This must be their breeding ground,' he thought, his eyes scanning the room for anything of value.

Among the clutter, he noticed a faint red glow coming from beneath the nest.

Intrigued, he approached it casually.

However, before he could reach it, the ground began to shake violently.

Suddenly, thousands and thousands of rats surged from every direction, surrounding him completely.

This swarm was at least Five times larger than the previous one, a writhing, snarling mass of teeth and claws.

In an instant, the wave of rats engulfed him.

His body vanished beneath the horde as they bit into him ferociously, their crazed red eyes glinting with malice.

The sound of gnashing teeth and scurrying feet filled the cavern, creating a disgusting grinding sound as they tried their best to devour his bone.

'These things are annoying,' Reign sneered in contempt.

Before the rats could surround him, he covered himself with an Exoskeleton.

Enhanced with his negative energy, it became impenetrable from their attacks.

No matter how fiercely they bit him, they couldn't break through.

However, that didn't mean he would let them have their way unchecked.

'I'll train you two for a bit,' Reign mused, a good idea forming in his mind.

First, he unleashed another fire breath, clearing a path.

Then, with a powerful punch upward, he generated a shockwave that created a gap around him.

Using this moment, he summoned Arc and Shackler, who immediately went into battle mode.

Arc immediately showcased its improved ability as it summoned a lightning field around itself, killing thousands of rodents in an instant.

With more breathing room, Arc spammed Lightning Strike, quickly exterminating the rats before they could regroup.

As for Shackler, being way weaker than Arc, it struggled to defend itself, relying on her chains to hold the rats at bay.

It was pitiful to watch her struggle, so Reign ended up assisting her, using his lightning to lower the load.

He gave her with some breathing space to fight back, so she could used her chains as multiple whips to slash through the horde.

'I think she's okay now' Reign stepped back, content to observe from the sidelines as his two servants grew more and more comfortable with fighting the horde.

Their movements became fluid and coordinated, showcasing the progress they had made through the fight.

As they battled on, Reign couldn't help but feel a sense of pride in their growth.

This was more than just a fight against rats; it was a valuable training opportunity for Arc and Shackler to hone their skills and become even more powerful servants.