The silence in the hotel suite remained, only punctuated by the breathing of Exia—the nickname known from the AI SERA—sleeping soundly on the bed, and Tabane swinging her legs on the chair.
"Ah! Hayato-kun!" Tabane greeted in a sing-song tone, her eyes sparkling. "Can I ask for something?"
"No," Hayato answered flatly. "I'm busy."
"But I came all this way!" Tabane protested, pretending to pout. "I even brought snacks!" She held up a bag containing various strange snacks. "And I****—(I can hear your Inner Voice)"
Her mouth was forced shut and she didn't even get to speak about what she wanted to say.
Without thinking, Hayato's instincts took over. He wanted Tabane gone. Now. He reached out, grabbed the collar of Tabane's lab coat, and pulled her out into the corridor with one strong tug.
"Waah!" Tabane exclaimed in surprise, but she didn't resist. Instead, her face showed an expression of curiosity and… a little impressed? "Your strength… this isn't ordinary human strength! You pulled me like Chifuyu!"
Hayato didn't answer. He used a bit of the concept "strong body"—not as strong as Saitama, just enough to be unmovable by an ordinary human. He kept pulling Tabane away from the door.
"Hayato-kunnn, I don't want to be kicked out!" Tabane protested, weakly trying to resist. "You're mean!"
But Hayato had already reached the end of the corridor, near the elevator. He released his grip. "Go home, Tabane-san."
"Tch, just you wait!" Tabane suddenly changed expression, from cheerful to slightly sinister.
"Don't think you can run away again tomorrow." She turned around and walked toward the elevator, still with that strange smile on her face.
Once the elevator doors closed, Hayato hurried back to his room.
"SERA, lock this room with high-level security. Soundproofing, vibration dampening, and all forms of external sensors."
"Done. Conceptual isolation layer active. No one can peek or listen from outside now."
Hayato sighed in relief, leaning against the locked door. He had just interacted with one of the most dangerous people in this world—and she knew something was different about him.
Inside the room, Hayato turned to SERA. "SERA, in your opinion, if I touched an IS, could I activate it like Ichika?"
SERA shook her head. "Yes, you could. But that's not the problem, Host." SERA paused, as if choosing her words. "The problem is… you could activate an IS without touching it."
"Huh?" Hayato fell silent.
SERA displayed a holographic diagram of an IS unit. "The problem is here: Arc of Embodiment is a conceptual power. Not magic, spiritual, or Ki. You don't emit mana, don't use chants, but generate reality around you. The world around you adjusts instantly to your will. In a world like the Nasuverse, reality itself might react defensively to you. But here, in the IS world, those machines are essentially systems that respond based on synchronization."
The diagram showed how an IS normally functions: waiting for the pilot's command, analyzing brainwaves, then adjusting. But then, a new layer—colored gold—appeared around the diagram, like a field altering everything.
"Tabane probably did something to let Ichika pilot an IS—because she cares about Chifuyu's little brother. But within a certain radius, you could alter, enhance, or even reprogram an IS. Even without touching it. The IS would open its system as if waiting for your command."
"So… the IS would experience anomalous resonance, considering me as a system admin?"
"Exactly. And it would adjust its functions based on your intent. For example, if you wanted its energy shield to not deplete or even become impenetrable, then the IS would automatically synchronize itself—even if it's a prototype unit that should have limitations."
Hayato nodded slowly, beginning to understand. "So Arc of Embodiment… is like conceptual magic that's dangerous to any world."
"Many other reincarnated protagonists choose cheat powers like Zanpakuto, Devil Fruits, time-stopping magic, or wish for power like Anos. But you chose the most fundamental—and most potentially disruptive—concept." SERA sounded a little annoyed, but also understanding.
Hayato cleared his throat. "Ahem, don't blame me. By the way… can Arc of Embodiment bypass security? Like this hotel door, or… a locked treasure chest?"
SERA brought up a new diagram: a digital security system with layers of passwords, biometrics, and structural locks. "Of course it can. But with limitations. You can open doors, password systems, biometric identification, even structural locks. Arc of Embodiment doesn't attack the system. Rather… it changes the 'rules of the world' so that the system believes you are the authorized person."
The visual changed to an image of a golden treasure chest from an RPG. "For treasure chests, it's the same. Usually chests have keyholes needing a physical key. But Arc of Embodiment can open them as if the chest were never locked in the first place. You don't need to pick or force it. The chest will open in an unlocked state, because you manifest the condition where the system considers you the owner or the key."
"What are its limitations?" asked Hayato, curious.
SERA pointed to a list appearing in the air. "What it cannot do: open 'Absolute Truths'—for example, a direct path to Akasha. Cannot override concepts belonging to Outer Gods, Alien Gods, or Beasts without major backlash. Mechanisms with 'strong concepts' can offer resistance or delay the process."
Hayato thought for a moment. "Will I have to fight such entities? Outer Gods, Alien Gods, or… G.O.D from One Punch Man? Coronzon from To Aru?"
SERA shook her head, her voice soft. "No, no need. You just need to maintain your existence if you meet them. Especially Outer Gods like Nyarlathotep—they might not consider you an enemy. They might be curious, because Arc of Embodiment doesn't work by following world laws, but reality follows your will. A power that manifests imagination is something difficult for them, even though cause-effect, space-time, and world laws don't apply to them."
That explanation gave Hayato some relief, but also made him feel smaller. "SERA, could I force—even later at Tier 3—to return to my world from this IS world? Using Shunkan Ido or intergalactic teleportation?"
"Not possible," SERA answered firmly. "Even if you remember your home or your world, the distance is too far. From this world to your home requires two inter-galactic jumps: first to the Strike the Blood world, then to the DxD universe. My suggestion: hone your conceptual power and increase your Arc of Embodiment Tier, even if slowly."
Hayato felt uneasy. "Could I create… a Gundam? To traverse galaxies with it?"
SERA nodded, but her voice was firm. "You could. But right now, you are being watched by The Watcher."
"The Watcher? Like in Marvel?"
"No. This is a formless entity—sometimes appearing only as an eye, sometimes as a vague humanoid. Its sole task is to observe and record, never interfere… unless an anomaly threatens the multiverse balance."
"Why be careful if they only observe?" asked Hayato, still naive.
"Fool," SERA hissed, annoyed. "Out there are Outer Gods. You think traveling galaxies in a Gundam won't cause anything? It's like lighting a beacon in the darkness! You'll attract the attention of all powerful entities across various universes. Remember, time doesn't apply to them. For you, one second is the fastest time in which the Arc of Embodiment concept appears. But for them, in that one second, millions of possibilities have already occurred."
Hayato was silent, then asked again. "Koro-sensei… he's not existential speed, right? He's still bound by world laws with 20 mach speed?"
SERA displayed a hologram of Koro-sensei moving super fast. "Correct. For humans or other strong beings, 20 mach is very fast. But for Outer Gods, it looks funny—like a turtle—because time doesn't apply to them."
The hologram changed to a diagram explaining 'Existential Speed'. SERA explained:
"Existential Speed is divided into several parts. First: Resonance Wave. If an enemy 'thinks' of an intent to kill, the resonance of that intent is read first, then Arc of Embodiment manifests protection before the attack occurs. The speed isn't in the action, but in the existential reaction to intent."
"Second: Pulse of Consciousness. Like in the Fate or DxD worlds. High-level entities like Zelretch, Ophis, or Beasts can respond before time flows, read possible futures, then choose the fastest existential path. One pulse of their consciousness equals dozens of steps of ordinary human action."
"Third: Movement in the Mental / Soul Realm. In worlds like Bleach or the Nasuverse, battles can occur in the mind but have physical impact. Time can be 'still' for the outside world, but hours pass in the soul realm. Speed becomes the ratio of information exchange between existences."
"Fourth: Response to Concept or Desire. For example, if you want to create a shield, you don't need long thought or chants. Arc of Embodiment directly answers the desire—before the opponent acts."
SERA looked at Hayato. "A simple analogy: consciousness as radar. High-level entities have extremely sharp radar, can 'see' waves of intent or concepts long before they occur. Ordinary people receive reality. They shape reality before reality hits them."
"Host, with Arc of Embodiment, you are on this path. Tier-2: can already respond at the level of basic intent or concepts. Tier-5 later: will be able to 'rewrite reality' even before that reality exists for others."
Hayato swallowed. "So… meeting entities on the existential plane is suicide?"
"Right now? Yes."
Hayato was silent for a long time, pondering. His thoughts swirled—the scale too large, the responsibility too heavy. But amidst all that, there was a sense of gratitude to SERA for patiently teaching him.
"Thank you, SERA," he said softly. "I… understand. It feels good to learn about the understanding of concepts."
He looked toward the window. The sun had completely set. Dusk had turned into night. Unnoticed, he had spent hours listening to this in-depth explanation.
"You're welcome," SERA answered, her voice softer. "Don't do anything foolish. You are still weak. But… you are different from other reincarnated protagonists. You chose to understand, not just to possess."
Hayato looked at the bed, where Exia was still sleeping soundly. Her face already looked calmer, more colorful. Fatigue finally attacked him too. The suite was large, the bed spacious. With a slow movement, he lay down on the other side of the bed, maintaining a polite distance, and closed his eyes.
---
In a Place Between Dimensions
Zelretch sat sipping tea while observing through his Kaleidoscope. The old man's eyes sparkled seeing Hayato's progress.
"Moving towards an interesting development," he murmured, a faint smile gracing his lips. "I can't wait to see his reaction later… when their children from the future come to the past, after he returns home."
He paused, then chuckled softly. "Oops. I probably shouldn't have said that. But… who cares? Let there be a little surprise waiting for our Anomaly."
He sipped his tea, enjoying the increasingly intricate drama he was watching.
Meanwhile, in the quiet hotel room in the Infinite Stratos world, Hayato Hayama fell asleep, surrounded by terrifying new knowledge and a girl he had saved—unaware that the threads of his fate had already begun to pull a future he never expected towards him.