Gray appeared inside his Atlanta base home back in The Walking Dead universe.
"Welcome back, sir," was the very first thing he heard coming from JARVIS.
"JARVIS, how long have I been gone?" Gray asked, looking around the familiar room.
"A little over two weeks, sir," JARVIS replied smoothly through the console speakers.
'No time difference between universes then, that's good,' Gray thought, feeling a wave of relief that years or months had passed in his absence. Taking a moment to look around his old living quarters, he planned to test something else now that he had figured out his world-travel power actually worked. He walked straight up to his ultimate external hard drive, the one containing all his movies, TV shows, and anime, and placed it directly into his system inventory. He planned to check whether he could freely bring physical items between worlds.
Next, he walked over and checked through his windows. He saw many people busy outside. Some of them tended the above-ground farmland, hauling baskets of fresh produce, while others stood high on the stone towers, keeping an alert eye on the perimeter fences. Gray briefly wanted to head outside to check on how things were going, but he ultimately decided to leave them alone for now. It had only been a couple of weeks anyway, and the fortress was running exactly as intended.
Finally done with his quick test, he refocused his mind. He focused on his Home Garden mechanics and willed the system to teleport him straight back to UA, leaving The Walking Dead world behind for a while.
Landing back at UA, the first thing Gray checked was his inventory. But alas, he wasn't as lucky this time; the external hard drive did not come with him into the My Hero Academia universe. Sighing, he didn't mind. If he needed to refresh his memory on any specific lore or future events, all he had to do was travel back to The Walking Dead universe using his plots of land and watch it there.
As for the other thing, he noticed a major detail when he opened his system interface. While he was physically present in his past world, the interface had temporarily reverted to the old interface he used when he lived there. This meant he also had full access to the specific powers and weapons he had bought during his first universe run. It turned out to be an incredibly good, successful test.
After thanking Aizawa and taking Eri off his supervision, they went back to their private room to watch a few movies on his laptop, passing the remaining hours comfortably before the Saturday evening training dimension officially became available.
At 6:30 PM, Gray heard a loud knock on his door. He opened it and found Mirko. She had arrived at the school a few moments earlier, and after not seeing Gray anywhere around the main campus, she had started looking for him. Eventually, one of the passing teachers pointed her in the right direction and told her where his private staff quarters were.
"Mirko," Gray said, stepping aside to let her into the room.
Mirko walked right in and went straight over to Eri. Apparently, the two of them had grown significantly closer while spending time inside the previous thirty-day Training Dimension cycles. Mirko couldn't visit her too often in the real world because her hero work was in a completely different city, but she already had plans to relocate her base closer to Musutafu later on; of course, she hadn't said a single word about that to anyone yet.
Seeing that it was almost time, Gray checked his system clock and started walking over toward the main training building, where a large bunch of UA high schoolers was already gathered outside the doors. The specific rules Nezu had laid down required any student who wanted to join the extra training to have an official petition signed by their parents first. A few parents in the civilian districts were deeply skeptical of Gray after watching the constant news broadcasts, so they flatly refused to sign anything.
So far, every single student from Class 1-A was present in the crowd. That was honestly all Gray cared about anyway. If the other parents couldn't see past the media frenzy to realize that he wasn't actually a villain and was willing to help their kids become stronger, then Gray was perfectly content to let those other kids stay mediocre in their training.
Once the clock finally hit 7:00 PM on the dot, Gray stepped up to the front and willed the Training Dimension gate to open. As the massive, swirling blue spatial portal materialized out of thin air right in front of their eyes, a few of the newer freshmen gasped in awe. Mirko, once again, was the very first one to jump straight through the gate without a hint of hesitation. She had seen the results of the past two training sessions firsthand, and she was ready to continue growing stronger inside the void.
When the last student and teacher went through the portal, Gray stepped in with Eri cradled securely in his arms. Once inside the void, he noticed the students looking around in awe at the dimension's endless, glowing expanse. The second the blue portal closed behind them, sealing them into the pocket world, Gray set Eri on her feet. He focused and flew high into the empty sky to address the crowd below.
"You guys will spend the next thirty days training in here," Gray's voice boomed out clearly across the open space. "If anyone needs anything at all, first go straight to your homeroom teacher, and then they will come directly to me." He paused, gesturing behind him as he willed two massive structures to rise. With a soft pop, two clean apartment complexes materialized out of thin air. "Behind me will be your sleeping rooms. Boys will be on the left; girls will be on the right."
Gray's eyes swept the crowd, locking onto the short-statured boy and the blonde electricity user. "Mineta. Kaminari. If I catch anyone trying to snoop or spy on the girls' block, I will personally give out severe punishments. So just keep that in mind before you try anything stupid."
Turning away from the shivering boys, Gray floated back down and turned towards all the gathered UA teachers. "You guys have spent a week with your students now, so let me know what you want to do first."
Aizawa was the first one to step up. "I'm thinking we have them all do the exact same physical training Midoriya has been undergoing. They desperately need to train their bodies before we even think about moving to Quirks." He stopped for a few seconds and looked over the freshman class. "A few of them are ready to train their Quirks right now, but we can have them train their bodies first."
Vlad King nodded from the side, crossing his arms as he gruffly said he completely agreed with the plan.
With the curriculum locked in, Gray turned to both of the homeroom teachers. "Take your students and bring them straight to Master Roshi to begin their physical conditioning."
Mirko had already left the group in a blur, rushing off toward her designated zone to begin her own high-intensity Rokushiki drills. Gray looked down at Eri, deciding it was finally time to start checking on all the available system options he had stored away to begin her mental health healing process. He scrolled through the psychiatric and medical options, stopping as he recognized a specific name: Hannibal Lecter.
Seeing that summoning the legendary specialist would cost him a meager 50,000 gold from his massive balance, Gray decided to try it. As far as he remembered from the TV show, the man was a brilliant, top-tier clinical psychiatrist, if you could forget about the minor detail of him being a cannibal, of course.
While the fifty-odd UA high schoolers were already being marched away toward Master Roshi's sector for their physical labor routines, Gray willed the system to spawn Hannibal into reality. The doctor materialized smoothly onto the grass, wearing a perfectly tailored three-piece suit. He looked around the sterile white dimension with sophisticated curiosity before introducing himself to Gray with a polite bow. He asked if Gray would be his primary patient, and Gray simply shook his head.
Gray turned around and pointed towards the little girl sitting quietly on the beach. He walked over with the doctor, getting Hannibal up to speed regarding her history, the Shie Hassaikai experimentation, and the deep psychological trauma she was harboring. After listening to the brutal clinical breakdown in silence, Hannibal nodded along, his expression composed.
"I can help her," Hannibal said smoothly. He focused his intent, and with a soft ripple in the air, a beautiful brick building materialized nearby. Inside was a flawless, pristine replica of his high-end office from the show, complete with dark oak shelving and leather patient chairs.
Before Gray went to fetch Eri for her first official meeting, he stepped into the doctor's personal space and told Hannibal one thing. "No cannibal bullshit, got it?"
Hannibal offered a refined, charming smile. "Of course, Mr. Gray. I am a professional."
Gray knew the Training Dimension's safe parameters wouldn't really allow the doctor to hurt Eri anyway, but he decided to sit through the entire first session right there in the room with her, just in case the sophisticated psychiatrist tried to pull any weird mind games.
Once Eri's session ended, Gray went over to one corner of the dimension and willed a space big enough for his own personal training. He instantly turned Super Saiyan, his hair flashing into bright, vibrant gold as a wild energy aura erupted around him, before he started fighting Super Cell. Thanks to the intense training sessions he had undergone, he was somewhat used to the form. He focused on energy control, using less and less stamina, trying to keep the transformation active without wasting a single drop of his Ki.
Over the next few days, everyone grew into their own routines inside the void. In the morning, the fifty-odd students from both Class 1-A and 1-B would report directly to Master Roshi to begin their grueling physical conditioning. Eri had her private therapy sessions with Hannibal Lecter three times a week, showing steady progress under the doctor's quiet guidance, while Gray continued pushing his boundaries to master the Super Saiyan transformation.
After two weeks, Gray spent some of his time roaming around. The students had about six free hours a day to do their own thing; they could either relax on a generated beach sector or use the time to rest and sleep in their designated apartment dorms.
During his walk, he came across Izuku. Over the past two weeks, the green-haired kid had been forced to complete every single one of Master Roshi's drills with his personalized weighted clothes upped to a dense 2x gravity. Gray had kept his word about doubling his training since the boy had "cheated" and bypassed the 10% limit during the Battle Trials. Izuku was exhausted, but his muscle mass was adapting at an unbelievable rate.
Walking over to the boys' dorm complex, Gray knocked on the doors and told them all to get ready, since he planned to take them on a small trip. He did the exact same on the girls' side, gathering the entire freshman group outside the apartment blocks.
Once they gathered outside, Gray took them to Mirko's private training site and told them to sit down and observe how a top pro hero moved.
Mirko had been sparring with Black Arm Zephyr. The stern, muscular instructor continued drilling the Marine Rokushiki six powers into her movements, throwing heavy, precise strikes that she had to constantly deflect or match. She seemed to be almost grasping the core foundation of the legendary techniques, her body moving like a white blur across the grass.
When Mirko finally finished her training for the day and wiped sweat from her forehead, she noticed all the UA kids looking at her from the sidelines in awe. She offered a confident smirk, walked over to the front of the crowd, and gently ruffled Eri's hair. Then she headed to her private dorm block to take a shower.
With the show officially over, the students dispersed across the sectors to do their own thing during their free hours. Gray swept his eyes over the retreating crowd, a small smile forming as he checked his notebook. He walked around the field, grabbing a few specific people he wanted to introduce to highly specialized teachers to kickstart their unique Quirk training.
Gray went around grabbing kids left and right. First, he went for Bakugo, Todoroki, Kirishima, and Izuku. He took them all to his own training space and started off with Bakugo.
"Alright, we'll start with you. Your Quirk is explosions, correct?" Gray continued. "Can you make explosions out of anywhere in your body, or just your palms?"
"Just my palms," Bakugo replied, clicking his tongue.
"Okay," Gray said. He made a metal barrel appear with hot water in it, choosing to deploy the exact same conditioning method he had seen the UA faculty use during the training camp arc in the anime. "You will put your hands in there to expand your sweat glands, and you will continuously throw explosions into the air. Do it until you drop."
Before Bakugo could even open his mouth to complain about the drill, Gray snapped his fingers and made a few figures materialize directly in front of them: Roy Mustang, Deidara, and Shinra Kusakabe. Gray asked them to give the boy a quick demonstration of what they could truly do. Roy snapped his fingers, making massive, towering walls of fire and explosions erupt in seconds. Deidara molded clay into intricate flying bombs, while Shinra sped around the entire training sector in a blinding blur, propelled by fire explosions blasting from his bare feet.
"Once you finish your morning training, I will have you learn under them," Gray said. He then continued down the line. "Izuku." Gray pointed toward Monkey D. Garp and Black Arm Zephyr, who stood in the background. "With them." Gray knew that if Izuku could successfully adapt his body to handle 100% of One For All without breaking his bones, he'd be more than strong enough to execute the high-speed Rokushiki marine techniques. And once he eventually awakened the hidden quirks from the past users, he'd be stronger than ever.
For Kirishima, Gray made Po and Bang take over. He wanted the teenager to learn that true defense wasn't just about taking a punch like a brick wall; he needed to absorb the fluid parries of the Water Stream Rock Smashing Fist and the redirection styles of the Dragon Warrior.
And finally, for the very last one, Todoroki. Gray made only one person appear from his system database: Uncle Iroh. The half-and-half kid still stubbornly refused to use his left side in combat out of hatred for Endeavor. Gray knew that if Uncle Iroh could guide Prince Zuko through his inner turmoil and make him a better person, then breaking through this high schooler's would be a walk in the park.