A/N: Tsume is Dr. Jekyll and Niko is Mr. Hyde. XD

https://www.youtube.com/watch?v=Ej8or-DfrIY

...

Razor: Umm...What is this?

When Giran said he wanted to speak with assassin. She did not expect for him to bring a child with him. By the looks of things this child was mentally unstable. He smelled like...DEATH.

Razor: I always knew you was unfaithful Giran. So whose the unlucky lady that you end up knocking up.

Giran: Very Funny, Razor. This is Niko Nikomatsu. My new young charge. You'll be showing him the ropes of training and assassination.

Niko: HIIII~~~~! :D

Razor didn't like the kid one bit. Not at all.

Razor: (I get the feeling Giran is raising a little terrorist that will bring nothing but horror for everyone.)

Niko: Kehehehe~! ':D

*LATER*

Kyoto Middle School.

Teacher: Alright everyone. I would like to make an announcement. We have a new student joining us.

Niko:...Hello. My name is Yamikage Tsume. My quirk is shadow claws. Pleased to meet you~! :D

In the daylight,
I'm your sweetheart,
Your goody-two-shoes prude is a work of art~!

Tsume made friends...He made enemies. He loved his classmates...but the exact same time...

He hate them. Everyday was the same thing.

"What kind of quirk do you have?"

"My quirk is better than yours..."

"Hey Tsume, stay away from that boy...I heard his quirk is villainous...You're better hanging out with people like us~!"

"Hey Tsume, I heard that girl is a mutant. Better watch your back. You don't want to be around people like that..."

Quirk. Quirk. Quirk.

Mutant-type Quirks.

Quirkless Discrimination.

No matter where he go...it was all the same...

They all assume that he would act like them. The same people who seem to enjoy sticking to their preferences and discriminate against those who are different from them.

Niko just giggled.

Niko: My poor...stupid...
classmates...you don't know anything about me~!

But you don't know me,
And soon you won't forget,
Bad as can be, yeah you know I'm not so innocent!

They all assume Tsume Yamikage was just another student with an average quirk. To them, shadow claws were not all that bad. Unlike some people at a church he massacred not too long ago whom believe it was sin.

But tbh, after spending a couple of months at Kyoto Middle School. He was starting to get bored of this life.

School life is not fun. Especially if all the students and teachers talk about are quirks.

Quirk. Quirk. Quirk.

That's all he hears.

Niko: So boring...

Better beware I go bump in the night, Devil-may-care with a lust for life, And I know you, Can't resist me, Soon though you, are so addicted! Boy you better run for your life!

So how about...he speed it up a bit and make things more fun~!

So...he made a gathering of all the students who were treated poorly by their peers.

Those who have "villainous" quirks.

Those who are mutants and treated lesser.

Those who have no quirks at all.

In order to get their trust, Niko made them all believe he was on their side. So he put his plan to the test.

Niko: Hey...

Students:...!

Niko: Let's Talk~!

Niko's manipulation upon the school begin.

....

It was a nightmare scene. Niko had corrupted so many students that had raised hell upon the school. He laughed his ass off as they started killing multiple students and teachers.

One by one.

Blood.

Death.

Murder.

Kyoto Middle School...Turned into a school of screams.

Welcome to the nightmare in my head, (Oh god!)
Say hello to something scary,
The monster in your bed, (Oh god!)
Just give in and you won't be sorry,
Welcome to my other side,
Hello it's Mz Hyde!

Niko: Nyahahaha!

Soon the world will know his name!

Niko: Oh~! I'm starving. I want some sushi~!

I can be the bitch,
I can play the whore,
Or your fairytale princess who could ask for more!

Niko: Ahhhhhh~! Miko-chan! I love him so much~~~!

After joining the League and commiting his mutual killing. Niko gained a crush. A yandere crush on a hero boy in Class 1-C of the hero high school, U.A.

Mikoto Yukimura.

He dugged up some info about the boy.

He's the son of the Ice Devil Pro-Hero: Yuki-Onna, Fumiko Himura Yukimura and Quirkless Former Ninja, Tohru Yukimura Ashikaga.

Niko wanted nothing more but Mikoto.

Because the boy piqued his interest...

A touch of wicked,
A pinch of risqué,
Good boy gone bad, my poison is your remedy!

Overtime, Niko had begin to strike fear into the hearts of so many people. Whether it be civilians, heroes, or villains.

There were so many people that wanted him in prison or dead. While there were others who wanted to chop him up in little itty bitty pieces until they could carry out their sick twisted ways to find out more about him and his quirk.

But nonetheless, he kills them. Turning everything into his own personal death trap.

Just like how he made the original Class 1-C fall~!

Niko: Who knew profiting information was so much fun~! I can thank Giran for that~!

Better be scared, better be afraid,
Now that the beast is out of her cage, And I know you, Wanna risk it, Soon though you, Are so addicted! Boy you better run for your life!

Niko continued his terrorists ways.

Once he gotten so many prisoners in Tartarus were now under his control by using shadow corruption. Tartarus...

The place that holds all of the most dangerous criminals in all of existence in the history of Japan.

One of them was the Takami Thief, who was well known all across Japan for robbery and murder. He knew they all wanted a piece of meat by beating up a couple of heroes.

Niko: Alright fellow prisoners~!

Niko have made sure the locks have been destroyed and the prisoners are now all free from Tartarus.

Niko: I know all of you are eager to work off all of your bloodlust but before you start killing each other. I should remind you all that you shouldn't be killing and fighting with each other. There's a prison right above us that is full of our fellow prisoners and guards. So let's all work together for now and kill all of the guards and destroy this prison!

Prisoners: YEAH!!!!

Welcome to the nightmare in my head, (My god!)
Say hello to something scary,
The monster in your bed, (My god!)
Just give in and you won't be sorry!

Guard: What's going on here?!

Niko grabbed the guards coming at them and pulled into a vicious sharp clawed hug.

Niko: Oopsie~! You guys hear that?! Sounds like fresh meat have arrived~!

Screams came out of the vault before they were cut off. Then the prisoners burst out of the vault racing up to the floors above to kill more guards. A pair of prisoners carried the heads of the guards leading the charge.

Welcome to my evil side.

Hello it's Mz Hyde~!

Hello it's Mz Hyde!
Hello it's Mz Hyde!

Niko will never stop...Until the whole world falls into nothing but chaos and destruction. So he begin to corrupt the world. He likes to bring out the worst in people! See the negativity on their faces. Hear the lamentations of their women!

I'm the spider crawling down your spine...Underneath your skin. I will gently violate your mind, Before I tuck you in!

Niko: Whoo-Hoo~! So much fun! Fun! Fun! Fun! Because I love chaos and despair! There's no reason for it! And nothing's holding me back! Nothing to stop me, I'm all the way up!

....

Tsume:.....*Looks into the mirror*

.....

Put on the blindfold
There's no way to be sure,
Which boy you'll get to know!

Niko: *DEMONIC* It's me Tsume, I swear!

Tsume: O_O?!!

Niko: Welcome to my world~!

Everything had turned into a death trap.

The world has fallen into chaos. Thanks to the actions of one mischievous boy.

Using shadow corruption would be a nightmare no one ever wanted to see. Angra Mainyu, in exchange of freeing him and he would free Tsume as well. Knowing that everyone who has given up hope in his so called friends, heroes, and family to save him, agreed.

He made a deal with the devil and turn Japan into his personal Slaughter House. He used, abused, and corrupted many who then freed theirselves through sin, destroying everything in path.

"Chaos"

"Destruction"

"Despair"

"Greed"

"Corruption"

Welcome to the nightmare in my head, (My god!)
Say hello to something scary,
The monster in your bed, (My god!)
Just give in and you won't be sorry!

Niko blackmailed many people in the past. Geysis was one of them.

Niko: Hahaha! Did you think you could take me down, Sensei~! It's going to take more than that to stop me!

Geysis: Y-You! What have you done to my students!

Niko: *Gasp* I have no such thing to receive such an accusation...well pretty much selling their info to the PSC. Now that they know those kids are "dangerous" to be around. They're taking matters into their own hands

Geysis: W-Why would you?! What the hell is your goal in all this?!!!

Niko: Oh nothing much. Just to see the world burn. That's all. I wonder how it will go. Maybe it go out with a bang! Ya know! Like the Big Bang Theory! Man I love that show! Have you ever watched it?!

Geysis: Take this seriously! I should have you arrested!

Niko: Oh~? Even if you did had me arrested. Wouldn't that mean you also suffer for the crimes as well.

Geysis:.......Eh?!

Niko: Think about it. You work for the PSC, too, right? Imagine what could happen if your fellow heroes found out. It's already bad enough your former students blame you for the cause.

Geysis:....

Niko giggled before stepping on Geysis' head.

Niko: I suggest you watch your mouth. Unless you want to lose more of the people that you care about~! The PSC is the place that lives off of corruption. I'm just doing them a huge favor.

Geysis: Don't Tell Me...You're also blackmailing them...How are you doing all this...? You're just one boy...

Niko: Kehehehe~! Oh Geysis-Sensei~!

Niko pulled his face up to his with his claws threatening to cut him.

Niko: There's more to me that meets the eye than you can ever imagine~!

I'm the nightmare that lives in everyone's hearts.

The nightmare in my head, (Oh god!)
Say hello to something scary,
The monster in your bed, (Oh god!)
Just give in and you won't be sorry!

The shadow slasher watches as his corrupted shadows flew into the middle of the crowd before landing, crushing some under its clawed legs, devouring some through his darkness, and simply murdering others with his claws. Heroes didn't even bad enough time to save them.

Panic set in, and the crowd began to run in all directions.

He smirked baring through it all.

Niko is Tsume Yamikage's evil side.

Niko: Welcome to my evil side!

Hello it's Mz Hyde!

Hello it's Mz Hyde!

Niko: NIKO FUCKING NIKOMATSU! AKA THE PINNACLE OF CHAOS AND DESTRUCTION! All I want is corruption and there is no reason for it~!