"Huff... huff... I have to make it. Please."
A boy wearing a blue baseball cap was hurrying down a flight of stairs. Suddenly, his foot slipped. Losing his balance, his body lurched forward, and he tumbled out into the air.
Seeing the boy about to strike the ground head-first, many passersby winced and shut their eyes. Fortunately, at the critical moment, a pair of slender arms reached out from the side and caught him firmly.
"...I-I'm saved." Still shaken, the boy looked up to see a face of perfect features. Naturally introverted, he stammered in a low voice, "Th-thank you for saving me."
"You're welcome. You were trying to catch the elevator, weren't you? Want to come with me?" Aomori looked at the youthful boy before him with a smile and set him back on the ground.
From Aomori's smile, the boy felt an incredible sense of warmth and kindness. He couldn't help but nod.
"Good. Let's go then. Watch your step."
"Okay."
They quickly reached the elevator bay on the floor below, but the floor indicator was already stationary at B2.
"We were a step too late..." The boy didn't hide his disappointment.
"Don't worry. It'll be back up soon."
"Even if it comes up, he'll probably be gone by then."
"Are you going to give up, then? Or will you keep moving forward until you find the person you're meant to meet?"
"I..." The boy hesitated for a moment, then slowly nodded. "It's still early. I'll keep looking."
"You won't regret it."
Just then, the elevator ascended and the doors slid open before them. It was empty.
"Let's go."
The two stepped inside. Before they could even press a button, the doors closed on their own, and the elevator began a rapid descent, causing the boy to cry out in alarm.
When the elevator stopped and the scene outside was revealed, the boy's eyes widened in shock.
"Where... where is this?"
Before them lay what looked like a train station. Using the platform where the elevator stood as a starting point, over a dozen tracks branched out, stretching into the unknown distance. On the tracks, only two strange-looking trains remained, yet to fully depart.
"No time to explain. Get on the train, quick!" Aomori grabbed the boy's arm, lifting him off the ground. In the same breath, he sprinted forward, catching up to the train in a blink and leaping onto the rear carriage.
Amidst the thundering roar of the tracks, they plunged through darkness and emerged onto a vast, open plain.
Looking at the boy's dumbfounded expression, Aomori smiled and said, "Welcome to the Digital World, Koichi."
…
"Legend has it that when it was first born, the Digital World was filled with chaos. After a long, long time, a Lucemon appeared and brought order. Sadly, Lucemon eventually fell into depravity, and its tyranny sparked a rebellion among Digimon. Ten of the strongest Digimon joined forces to seal Lucemon away; they were honored as the Legendary Ten Warriors."
On a podium made of a tree stump, a Wizardmon was speaking eloquently about the history of this Digital World. "Though they perished in that battle, the Ten Warriors left their power behind, what we now call the Warrior Spirits. This is our trump card against the dark forces!"
"Teacher, I have a question," the star student Koichi raised his hand and asked. "What exactly are the 'dark forces'?"
"Good question," Wizardmon said with a solemn face. "The dark forces are the Dark Army led by the fallen Seraphimon. They seek to rule this world."
"?" Aomori, who was listening in, showed a look of surprise.
After defeating God, the world of One Punch Man was cleared of its existential crisis. Of course, Monsters would still appear occasionally, that was a fundamental mechanic of that world that even Aomori found difficult to change. However, with Blast back on the team at the Hero Association, the heroes could easily eliminate any troublemaking Monsters even without Aomori there to oversee things.
Consequently, having some free time, Aomori focused on his dungeons. This time, he had entered the Digital World. Many years had passed since he last left, and the timeline had reached the beginning of the main plot.
Aomori had happened to save the key character, Koichi, and brought him to the Digital World. It was only the second day, and they had chanced upon a Wizardmon, whom Aomori asked to explain the world's history.
He hadn't expected the Digital World to have undergone such earth-shattering changes, which took him by surprise. I seem to recall that Cherubimon was the one who turned evil. Why is it Seraphimon now? Could it be because of me?
On the podium, Wizardmon continued: "...After Lucemon was sealed, the Digital World was governed by the Three Great Angels. Among them, Seraphimon and Ophanimon were responsible for managing Human-type Digimon, while Cherubimon managed Beast-type Digimon. However, as conflict intensified between the types, Ophanimon showed favoritism toward Cherubimon. This filled Seraphimon with resentment. Ultimately, he plotted to capture Ophanimon and Cherubimon, falling completely into darkness. The Digital World has fallen into shadow once... twice... yet again."
"..." Aomori remembered now. When he left the dungeon originally, he had left a note telling Ophanimon to pay more attention to Cherubimon's mental health. As a result, he had neglected Seraphimon, causing him to blacken instead.
"Not only that, but a power calling itself the 'Steel Empire' rose silently, taking control of nearly half the Digital World and standing as an equal rival to Seraphimon. Their leader is the incredibly powerful BlackWarGreymon."
"Steel Empire? BlackWarGreymon?" Aomori cocked an eyebrow, sensing a familiar scent. "Is it a coincidence?"
Regardless, he intended to go and meet this Steel Empire.
…
After bidding farewell to Wizardmon, Aomori led Koichi toward the headquarters of the Steel Empire army.
"Aomori-nii, can I really find Koji here?"
"Of course. He's an outstanding person, so he'll be chosen to become the Warrior of Light."
"Warrior of Light?"
"You heard it just now, didn't you? The Warrior Spirits are very strong. If you don't work hard, you might be overshadowed by him. Don't you want to be a cool older brother who protects his younger brother?"
Kouichi gritted his teeth and nodded. "I do. I really want to stand before him and confidently say, 'I am your older brother'!"
"Then you need to work harder to master the power I taught you."
"Yes!" Kouichi nodded, picking up a black crystalline body and pressing it to his forehead.
A thick dark energy enveloped him, transforming into a set of black armor with dragon-like features. It covered his entire body, head included. This wasn't a standard dark-attribute Warrior Spirit, but a custom version Aomori had created himself, a "little toy" he made since he found Koichi to be a kindred spirit.
His dark energy was inherited from the Dark Warrior, but Aomori's current understanding of dark energy was no longer inferior to it. Thus, the custom armor he created possessed significant power.
"Koichi, remember: darkness does not represent evil. To master true darkness, the key lies in understanding the principle of 'dwelling in the dark while yearning for the light'."
"Dwelling in the dark while yearning for the light..." Koichi nodded thoughtfully.
"Hmm, some decent opponents are coming. Go meet them."
"Yes!"
Koichi leaped high, entering the town ahead in a few bounds.
"Familiar machine-type Digimon." Aomori took out the Laptop from his system backpack and asked Akihiko Kayaba inside, "Is it you, Kayaba?"
Akihiko Kayaba emerged partially from the screen and said, "I need to import my information stream into this Digital World to capture the information of my other self."
"Never mind then. I'd rather explore it myself; it feels more like a surprise that way."
"You're the boss."
Having learned from the last experience, Kayaba returned to the Laptop after chatting with Aomori for a bit. Hearing the booming sounds from up ahead, Aomori started walking with a smile.
…
"Where did such a troublesome Digimon suddenly come from?"
Hearing that the vanguard had encountered strong resistance, LadyDevimon frowned in dissatisfaction. It had wanted to perform a great feat, so it had proactively applied to be the frontline commander responsible for territorial expansion.
To its surprise, bad news arrived after only a few days, stating they had been attacked by an unidentified Digimon. Not only did they fail to take the town, but many soldiers were taken prisoner.
"Even the strongest subordinate, Mammothmon, failed." LadyDevimon rose from its skeletal throne. "I have no choice but to take action myself. All forces, move out!"
At its command, nine warships took to the sky, heading for the front lines. They arrived over the blocked town in less than half a day.
"Execute Tactic A. Give those little ones down there a fire-coverage they'll never forget." LadyDevimon curled its lips into a seductive, wicked smile.
However, the expected barrage of fire never happened. Just as it was wondering why, two figures appeared before it. One wore black armor, matching the target image from the reports. As for the other… it was actually a human?
LadyDevimon scrutinized the human, feeling his appearance was somewhat familiar.
"This smile... this pressure..." LadyDevimon immediately recalled his identity. Its body reacted faster than its brain.
With a thump, LadyDevimon fell straight to its knees, teardrops as large as beans dripping from its eyes. It crawled toward the human, wailing: "Great King, Great King, is it you?! You've finally come back! This little one missed you so much!"
"..." Aomori kicked the pouncing LadyDevimon to the ground and guessed, "Are you that little DemiDevimon that turned over a new leaf back then?"
"Yes, yes!" Despite being kicked, LadyDevimon wasn't angry. Instead, she touched her swollen cheek with pride. "Thank you for the gift of your love, Great King. You truly kept this little one in your heart! I am so incredibly happy!"
Koichi, standing nearby, was so stunned he deactivated his transformation. It was the first time he realized that Digimon could be just as shameless as humans.
"...With this level of flattery, I'm certain I haven't mistaken the person." Aomori walked to the high seat and sat down, sighing. "I didn't expect you to have evolved into an Ultimate level."
"It's all thanks to your cultivation, Great King." LadyDevimon moved its knees quickly to Aomori's feet, blinking up at him as it proactively shared its experiences over the years. "After you disappeared, Kayaba-sama forcefully took over all power and had us follow the script you left behind. In the end, we successfully helped the DigiDestined save the Digital World."
"Later, we encountered an enemy called Millenniumon. From it, we learned the news of your exile."
"You met Millenniumon? It was indeed the culprit that exiled me to this Digital World." Aomori nodded. "It seems you defeated it?"
"Yes. We couldn't beat it at first, but later... ahem, with the help of a child named Ryo Akiyama, we finally defeated it." Under Aomori's gaze, LadyDevimon spoke the truth of what happened.
"And after that, you flourished under Kayaba's leadership and even moved into other Digital Worlds?"
"Mhm, Great King, your brilliance is unparalleled. This little one is in awe." After flattering him, LadyDevimon expressed its loyalty again. "We were worried about your safety, so we wanted to search other Digital Worlds for your tracks. Fortunately, heaven had mercy and finally let me find you. Great King, you've suffered these past years, boohoo..."
By the end, LadyDevimon was in tears, causing Koichi's eyes to redden with sympathy. Aomori-nii actually has this kind of past. No wonder his eyes are so full of life's hardships. But at least they're reunited now. Although they had only been together for a few days, Koichi truly viewed Aomori as an older brother.
"Alright, that's enough."
"Yes, Great King." LadyDevimon immediately stopped crying, revealing a sycophantic smile.
"..." Koichi looked up at the sky. Koji, where are you? The adult world is so hard to understand...
"It wasn't just to find you, but also to catch that criminal Millenniumon and cut it into a thousand pieces to vent the anger trapped in our hearts!"
"You've worked hard." Aomori nodded slightly. "I heard the leader of the Steel Empire is BlackWarGreymon. He should be that blue Greymon from back then."
"Mhm, Great King, you are truly insightful." LadyDevimon nodded vigorously. "He's a battle maniac. All these years, he's the only one who evolved into a Mega level without Kayaba-sama's help."
"Where is he now?"
"Well, he's definitely at Seraphimon's door blocking the entrance. He feels uncomfortable if he doesn't fight for a day."
"Good. He has mastered the secret to becoming stronger. Truly a Digimon I raised myself." After praising him, Aomori asked the question that had been circling his mind for a long time: "What about Gatomon? Is it here too?"
"That one..." LadyDevimon tried its best to suppress the annoyance in its eyes, saying with a smile: "It's not here. It's probably... maybe... likely in the Human World with its little master right now."
"Oh, really?" Aomori didn't say whether he believed it or not. He looked at LadyDevimon until she was trembling with fear before slowly saying, "Take me to see BlackWarGreymon."
LadyDevimon breathed a sigh of relief and nodded quickly. "Yes!"