In MHA with JJK powers.

As soon as All Might blasted through the wall, Hero Kamui Woods rushed in spreading his branches toward the stunned league of villains.

Everyone including Mechamaru was entangled in an instant, Dabi tried to burn the restraint but a flash of light suddenly rushed up at amazing speed, Grand Torino kicked Dabi on the back of his head knocking him out.

Not stopping for a second, Grand Torino appeared before Mechamaru and kicked his head as well, knocking them out.

Of course, Mechamru was just acting.

"Shigaraki--"

Before Kurogiri could continue, a thin razor-sharp string rushed into his body and immobilized him.

Hero Edgeshot!

Shigaraki was stunned, the sudden turn of events was completely out of his expectations.

The last boss suddenly invaded your home? How is this fair?

His eyes stared at All Might with visible hatred.

But All Might's next words left him stunned.

"Shigaraki Tomura.....my master's grandson."

His words stunned everyone.

All Might looked at the bound Shigaraki with a complicated gaze, filled with remorse and self-hatred.

"Forgive me for not being there for you...But I am here now..."

All Might extended his hand towards Shigaraki.

"So let's start over again, it's not too late."

He tried to put up his best smile, in order to convince his master's only blood relative to turn back to the correct path.

But all he got in return.

"Don't Fck with me!"

Was deep-seated, bone-chilling hatred.

The heroes present in the scene couldn't understand how such a deep and boundless evil could be emitted from a kid.

"You weren't there when I needed you....."

"And now you dare say that to me?! All Might?!"

All Might's eyes trembled, listening to Shigaraki's blood-curdling howls.

"Toshinori don't be swayed by him!"

"Y-yes Gran Torino..."

Listening to his teacher's voice, All Might suppressed his emotions, looking at Shigaraki with firm and unfaltering eyes.

But his change only seems to make Shigaraki even crazier.

"I know you are awake!"

His voice attracted everyone's attention.

"I refuse to believe these pieces of trash can stun you!"

A bad premonition hit the hero's heart.

"Are you even listening to me?!"

Shigaraki shouted at the top of his lungs.

For a moment everyone's heart skipped a beat.

And then.

Mechamaru's lowered head raised up.

'He was pretending?'

Gran Torino was the first to notice.

Staring at Mechamru in disbelief, remembering how he clearly knocked him unconscious before.

This was not the time to think of useless things!

For a fraction of a second, Mechamaru's green and Shigaraki's red eyes collided.

"Do it now! Let them feel pain!"

"Mechamaru!"

"As you wish, my friend."

Followed by his voice.

A giant metal palm broke through the earth and enveloped the place.

The police forces and heroes sitting outside on standby stared in disbelief at the sky-covering metal monstrosity that appeared before them.

It was a towering machine with three pairs of red eyes, impossibly massive, its silver body looming over everything, its dark silhouette gleaming under the fractured light of the cursed energy it radiates. 

Suddenly a flame erupted from beside them and attacked the robot.

It was Endeavour.

"There was no intelligence about such a giant piece of junk!", Endeavour shouted in a dissatisfied voice and attacked again.

Unfortunately, his flames did no damage to the metal construct.

"What?"

Endeavor was taken aback.

Jogo's cursed technique was out of his syllabus after all

Suddenly the metal giant opened his mouth and and declared its existence.

"Ultimate Mechamaru."

At the same time, on a nearby roof, All Might appeared, carrying Bakugo and the other heroes.

"That was a little close."

He said and carefully placed everyone on the ground.

"They had such a trump card.", Gran Torino muttered in a small voice then turned to All Might.

"Fortunately you were healed, but 'he' has yet to show himself Toshinori, so you should stay put for now and wait for him----"

Gran Torino's voice was interrupted by the massive explosion in the distance.

The giant blast was almost twice as big as Ultimate Mechamaru.

"I can feel it he's there!"

All Might gritted his teeth in anger.

"All For One!"

"It's bad! that's where Mount Lady and the other are!", Kamui Wood said in a worried voice.

"Go Toshinori! We will take care of it here!"

"Yes!"

With a giant leap, All Might rushed towards the blast location.

Inside Ultimate Mechamaru.

Dabi, Kurogiri, Toga, Magne Spinner, and Mr Compass were dumbstruck staring at the screen displaying the outside world in wonder.

Only Shigaraki's eyes displayed a sense of newfound excitement.

"Kill them Mechamaru! crush those bastards!"

Hearing his voice, Mechamaru didn't say anything but silently released limitless since All Might was gone.

Now that the two bosses were fighting, he could also start going crazy.

Ultimate Mechamaru's three pairs of eyes glowed and started raining down red beams of lasers below.

----

Behind the wall, Midoriya, Shoto, Kirishima, and Momo stood still tremblingly not daring to utter a sound.

The intense feeling of dread was enough to make them feel suffocated.

But it was natural.

Since the one behind them was the biggest villain in Mha.

All For One.

"Hahaha I was originally going to teleport them back.....but what a surprise you gave me Mechamaru...."

 All For One looked at the distant metallic figure with a smile on his face.

"What a cute toy you have created."

He seems to be talking casually as if the devastated surroundings and severely injured heroes had nothing to do with him.

The more he talked the more scared they became.

Suddenly Momo crossed her arms across her chest to find a feeling of comfort, but it was then that she noticed.

'K-Kurokai-kun is fine...?'

Her gaze landed on Kurokai who just stood in place, showing no sign of panic.

Seeing his calm figure suddenly gave her a sense of relief.

'I-it should be fine with right? Since Kurokai is here....'

Her body unconsciously leaned on his side,it was an instinctive reaction of the weak to seek the protection of the strong.

Feeling the soft touch. Kurokai was momentarily distracted, looking at Momo who was hesitantly leaning on him, he thought for a moment before wrapping his hand around her shoulder and pulling her closer to his chest.

But surprisingly, unlike what he expected, Momo didn't resist him at all, obediently letting him bring her close.

Listening to Kurokai's rythemic heart beat made Momo calm down, this was the first for her, suddenly the fear of greatest evil in her heart lessened significantly.

'.....It doesn't feel so bad.....'

Momo thought in her mind, lightly wrapping her arm around Kurokai's waist, she didn't even notice her chest was pressing against him.

Meanwhile, Kirishima and Midoriya were looking at them as if they have gone nuts.

'Excuse me?! But this really isn't the appropriate time okay!?!'

They screamed loudly in their minds, only Shota was excluded since his position wasn't beside Midoriya and was unable to see what just happened.

"Hm it seems you are here."

The sudden voice sent chilld down their spine.

'Did he discovery us?'

They all(except Kurokai) thought in horror.

Momo unconsciously tightened her grip around Kurokai, pressing her chest against his.

Feeling the soft sensation, Kurokai couldn't help but give All For One a big thumbs up in his mind.

"I will have you return everything! All For One!"

"Are you going to kill me again? All Might!"

Momo suddenly came back to her senses and hurriedly withdrew from Kurokai's embrace.

'Oh there party pauper is here.'