What is this Place!?

Japan was slowly covered in a purple mist. A undetected rift had broken open, unleashing thousands of A class monsters across the city. A ominous voice rang out across the small country as the mist revealed it's intentions. "Humans! Are you ready to become our meals?". The shockwaves from his voice rang across the entirety of Japan. Hundreds of monsters began rampaging throughout the country. But no one seems to care. No one was panicking, nor was anyone screaming.

Perplexed, the mist monster yelled, trying once again to gain their attentions. "Fools! Do you not realize that your deaths are imminent!?" This time, the screams were deafening. But they weren't from humans, it was from the other monsters across the country. The mist thought to itself, confused that the ordinary citizens of this place could repel his army. The mist checked the clock as he pondered. It was still early in the morning.

"Excuse me!" A voice rang from below, cutting off the mist's train of thought. Curious, the mist monster looked at the source of the noise. He looked like a regular salaryman, rushing to his job. "Can you lift this mist please?" He continued "I gotta get to my job by thirty minutes or else my boss is gonna fire me!".

"A mere human dares to request something of me at his death bed!" The Mist roared, picking up all of humans he could possibly hold. "Listen up heroes! Show yourself and stop attacking like cowards! I have thousands of hostages ready to die on my hand!". There was still no response.

"Aren't you being hypocritical here?" Asked the salaryman.

"Shut it!"

"You know, I was planning to wait for someone else to clean you up, but it seems like that's I'll have to take care of you myself"

"Blabbering your mouth now that you're about to die, eh?" The monster smiled. "Don't worry, I'll make your dead a painl-"

Before the monster could finish his sentence, the salaryman threw a punch at the mist, with the sheer wind pressure tearing a hole the size of a skyscraper through the monster. A explosion of sound echoed throughout the land as the man's punch went faster than the speed of sound, preforming a sonic boom.

"What the hell... are you?"

"Who knows? Now piss off before I'm late to my job!"

Before the monster knew it, thousands of the same holes tore through his body, throwing the mists into the cold outer space. It wasn't from that man alone. Every single punch was thrown by a completely different person.

"What the hell are you people!?" Was the last thing it said as every trace of the mist disappeared with a chaotic collection of sound.

The salary man, completely ignoring the monster's last outburst, was worried about something else. "screw this, I don't care if I have to pay a fine, I gotta hurry to my job!"

The man activated his super speed and water walking, speeding across hundreds of miles of the ocean in mere seconds. He was heading for California. While running across the Pacific Ocean he muttered to himself, "What the hell are the inspectors doing? This is why I shouldn't buy a house in such a rural area. But my wife seems to love Japan though." A fearsome monster was nothing more than a harmless to this world. Speaking of rats...

In the sewers of Japan, the mist monster slowly regenerated it's body. It thought to itself, what luck that some parts of his bodies floated down the sewers before the fight started. No, it wasn't even a fight. It was merely a one sided abuse.

"How dare some inferior humans do this to the Demon King of the 3064th Realm, Akai!?" Bellowed Akai, or rather, squeaked, for he only has a small puff of purple mist left.

________

I must get my revenge!

I opened my eyes as I scan around the sewers. I activated my thermal sensing, finding that there are thousands of creatures living down here. I must power back up. As I was surveying the maze-like structure of this so-called sewer, a mice ran across me, looking at me as if I was the rude one here. How dare such a puny creature cast it's gaze towards me-!? ... actually, this could be pretty handy. As fast as lightning, I strike at the mouse and fill it's lungs. I cast {Parasitic Takeover Level 1}, as half of my body traveled to the mice's brain and promptly took it over, with little to no resistance. I couldn't do it to the humans before because they were covered in a blanket of incredible energy, and my skill level wasn't high enough. I never bothered to upgrade this skill much because all of the monsters living in the 3064th demon realm had resistance to it. My race was quite common after all.

[Your Unique Skill, 「Desperation」has been activated and sacrificed! The next source of EXP will be multiplied a thousand-fold!]

[Bonus EXP obtained for Parasitic Takeover! It has been 3920 years since you last used this attack! Bonus EXP will be applied! Calculating that the user has become a Demon King! Multipliers will be applied! Calculating that there is more than one host within this body. Multipliers will be applied!]

[Parasitic Takeover has been leveled up to level 10]

[Parasitic Takeover has evolved into Complete Nervous System Takeover!]

[Complete Nervous System Takeover has been leveled up to level 10]

...

As it continued evolving, I took a look around the sewers. Nothing but rats and mice.

It seems like in this world, I can easily take over the smaller mobs. I'll have to stay here to build my strength for the moment.

Just then, I heard a hiss. There shouldn't be anything that powerful here though...

With my newfound body, I scampered over to where the noise originated.

I looked around the area, as I saw mice scattering, running as fast as their little legs could take them. It was one of my minions, the King of Cobras. While he was lower in rank in my army, he was nonetheless a A- ranked monster. It would be best if I recruited my fallen army. I walked over to it and began to give the Cobra commands.

"What are you thinking, to not bow down within my presence!?"

The cobra narrowed it's eyes, looking startled and surprised.

"Who do you think you are?" It replied. He obviously mistaken me for a mere rat.

"Your King. So kneel"

The cobra laughed.

"I don't know how you speak our language, but a mere rat try's to order me around!? I am the King of Cobras!"

With a hiss, it opened it's mouth and lunged forward. It's trying to swallow me in a single bite.. I dodged within a hair's breadth and jumped back.

"You dare attack your king!?" I roared

"You are no king of mine!" The cobra said with a hiss.

While I wouldn't die if the mice body died, I would still suffer the pain and mental damage.

Even if I disengage from this body to fight him in my mist form, it would be useless. He comes from the same world as mine, so he would be familiar to my usual mist attacks while I'm too weak to use it properly. I had no other choice. He opened his mouth as a warning and hissed. That was my chance.

I ran at full speed right into it's mouth, and slide down it's throat. His throat muscle swelled like a balloon in shock. He stopped, realizing he got exactly what I wanted. He began pushing we farther down his body. I forced myself to stop and disengaged from the body. Now, the rat has his body back. The poor thing squeaked and panicked as he tried to stop himself, but there was no way out. It was none of my concern anyways.

I tried to find my skill, but I couldn't. I searched through my skill page anxiously as stomach acid started filling up. I stopped the search as I realize the absolute monster it grew into. I activated the skill,

{Omnipotent Parasite Level 7}