Invasion

Silverman Gym - 5AM

After an hour's rest back at the castle was done, the group split to their destinations to continue on their mission. The van pulled up outside Silverman Gym where Izuku and the Kamado siblings would train their skills in order to toughen themselves up to take down the overlord and put an end to this invasion.

"Okay guys, we're here." Yusei stopped the van.

"Now, here is our plan of action." Eren gathered the group around. "We need to lace the gym's sprinkler system with sake. From what I just heard, invaders and clones are inside training to buff themselves up, meaning there's a possibility that we won't stand a chance against them."

"Good grief, this is gonna be tougher than I thought." Jotaro sighed heavily.

"So what do we do?" Asked Akira.

"Akira, you fly up to that rooftop and try and get into the sprinkler system with the sake. Once you do so, be sure to wait until Izuku, Tanjiro and Nezuko are done with their training so you can start a little fire with your Devil Beam."

The Devilman nodded in understanding as Eren turned to the trio of teens.

"In the meantime, you three go inside to hone your skills in your Quirk, swordsmanship including your Water-Breathing sword style and Blood Demon Art. You'll be more stronger during this time."

"Mmm!" Nezuko nodded, feeling determined to do so.

"We'll do our best, Eren." Added Tanjiro.

"For our world to be safe." Concluded Izuku.

With that, the trio left the van and headed straight to the large world-renowned gym to hone their fighting skills, while hoping to not run into any clones or invaders.

~~~

Inside the gym, the trio watched from a distance inside the reception. Sounds of working out were heard as various clones and invaders were boxing, doing martial arts, running and weightlifting.

"We don't wanna risk disturbing them. We might end up becoming victims." Izuku whispered.

"So how are we gonna train in secret?" Asked Tanjiro.

Nezuko pointed to an open door, leading to an office. There was an air ventilation shaft.

"This could work. That way they won't see us." Tanjiro praised his sister. "Nezuko, you're a genius."

"There's only one problem though..." Izuku trailed off as he noticed something moving out of the office.

A clone of a tall man of fair complexion with messy black hair and a very handsome profile, wearing a blue and white tracksuit. Not only that, but he appeared to be rather stronger than any invader, the gang had faced.

"We have to get past that Naruzo clone and be quick about it! He might be dangerous." Warned the dark green haired boy.

Both Kamado siblings nodded, before the trio slinked up to the office, sticking to the shadows as usual to keep themselves from being seen. Having reached the air vent, they removed the vent and began to crawl inside. The vents were like a maze compared to the abandoned funhouse section of Kaiba Land but the trio pushed onwards to navigate their way through it.

"Good thing those vents aren't too tight." Tanjiro whispered.

"I'll say." Izuku nodded, before seeing a light. "There's an empty gym room. Perfect."

Opening the vent, the trio entered the vacant gym room. Thankfully it was locked from the outside, meaning no invaders or clones would get in.

"Alright then," Izuku remarked, voice laced with determination and vigilance. "Let's get to training!"

~~~

Outside, Akira landed upon the roof of the building, sake in hand. He set off to tamper with the sprinkler system in order to get the job done as soon as possible.

"Okay, it should be here somewhere..." The Devilman opened up a panel and snuck inside. "Can't be too far away." Inside was dark and damp as he moved to dodge some pipes. It was also dusty and full of cobwebs, looking as if it hadn't been cleaned up. His eyes widened upon spotting the main for the sprinkler system before his mouth curled into a smirk.

"Bingo."

~~~

Back inside the gym, the trio were toughening their skills. Sounds of fighting filled the room as they supercharged their attacks on the training dummies while making sure not to overexert themselves. Their training went on and on until their powers were now improved.

"Great work out there." Izuku said, catching his breath.

"We'll be tough enough to take down the enemy, no doubt about it." Replied Tanjiro.

"MmmMmm." Nezuko nodded.

With their training complete, the trio returned to exit through the vent to escape the gym but not before they heard a clanking sound coming from the pipes inside the walls.

"That must be Akira tampering the sprinkler system. Better hurry along."

~~~

Outside the gym, the others waited in the van for the trio to come out of the gym building. Jotaro was on lookout duty in case any invaders or clones were on the prowl.

"See them yet?" Denji asked.

The Stand user shook his head in response. "They're taking their time with their training. At least, Akira's done his job."

"Look, I see them!" Yusei called out.

Without warning, the trio came running up the van, followed by Akira and entered the van as quickly as possible.

"Got the sprinkler system rigged?" Asked Eren.

"All systems go."

As if on cue, bloodcurdling death screams rang out from inside the building and the door burst open to reveal the Naruzo clone soaked in sake, becoming weaker and weaker.

"Step on it, Yusei!" Izuku yelled.

The turbo duelist nodded before slamming the accelerator pedal and drove off down the road as fast as possible. This battle was far from over.