"...Well, I don't think anyone would expect the person they're talking about to suddenly pop out like some kind of magician's trick," Kiba muttered. Even with his sharp sixth sense, he hadn't noticed anything until Kousuke spoke first.
"Yeah, how are you even here? I thought you already left the Underworld yesterday," Issei said. He remembered seeing him teleport away with Kuroka tagging along, and according to Shirone, her sister had turned into some kind of unseen bodyguard assigned to protect Seele from people that may comes to take her back. Kuroka had tried escaping, but somehow always found herself back at his house, as if trapped in a loop.
"Why? My friend was calling for me, so I thought it would be fun-Cough, I mean, why shouldn't I be here?" Kousuke replied with a kind smile, one that somehow felt ominous. He hadn't planned to intervene at first. Issei's progress was actually admirable; he had been just a normal guy a year ago. But the news about traces of the Demon God lingered in his mind, making Kousuke feels rather uneasy, so he decided to be more proactive. That was why he teleported over after spending the night playing games and other things with Kunou until she fell asleep from exhaustion.
"Were you going to say 'fun' just now?" Issei interjected.
"I said no such thing. Anyway… tell me if I'm wrong, but you want to get stronger quickly without going through all the boring training? Well… there is an easy way."
"Really?!"
"Yes. Actually… why don't you turn back into a human?" He said nonchalantly.
"...Huh? What do you mean by that?"
"So, you see, Sacred Gears were originally made for humans by the person upstairs, right? Meaning they were never intended for someone like you, a reincarnated devil, to possess. Normally, it shouldn't even be possible, yet somehow you can. That's because Heaven doesn't have anyone capable of maintaining the system. The person upstairs probably didn't want the knowledge falling into the wrong hands, that's why even Azazel can't fully comprehend how Sacred Gears work."
Kousuke explained while recalling what he learned from reading through the Fallen's research notes.
"I don't get it. What does that have to do with me turning back into a human?" Issei asked, confusion written all over his face. Kiba, however, seemed to have understood and nodded with an enlightened expression. 'So that's it, everything made sense now.'
"Since there's no one maintaining the system, it's basically gone bonkers and started allowing weird exceptions like you. And worst case? I have a feeling that sooner or later, Sacred Gears won't remain 'human-only' weapons." His voice lowered. "Basically, what I'm saying is—you'd become much stronger with a weaker body. It sounds weird, but the devil blood in you is restricting your full human potential. Sure, your current body is physically tougher, but that comes with a cost."
He paused, then added, "Here, let me give you an analogy: imagine you're a cyborg, half human, half machine. Yes, your body becomes stronger and capable of things no human could dream of, but it's not the same as moving your real arms using your own brain to command it."
"Um… I kinda get it, and also understand nothing at the same time," Issei said while clutching his head. "So you're saying being a reincarnated devil is bad for me? Even though it saved my life?"
"No. It definitely has its perks, so I get why many wouldn't hesitate. For example, your lifespan. Most living beings have lifespans, but devils age incredibly slowly compared to humans." Kousuke shrugged. "You can even conjure magic fueled by imagination. Honestly, devils have one of the best deals."
"Now you're just pulling my leg. First, you say it's a bad thing and now you're praising them. So what exactly are you trying to say?"
"Well, you see… I recently learned a lot about souls. And I accidentally found out that I do have a Sacred Gear as well. I even awakened it properly." Kousuke extended his hand, and a silver key materialized above his palm. From the familiarity of its aura, both Kiba and Issei could instantly tell, this was a real Sacred Gear, and it has the presence of a Longinus. "I call it Imaginary World."
"That sounds powerful. What does the key do?"
"Watch." Kousuke stabbed the key into the air and twisted. A portal formed instantly as the key was sucked inside. He turned back to them. "Come. Follow me."
Kousuke stepped through. Although hesitant, the two eventually followed. The moment they crossed, they immediately sensed the difference. It looked like a normal grassy field, but the air felt strange, similar to the Underworld, yet purer.
"Where is this? I feel like I could sleep forever just by lying on this grass…" Issei said, surprisingly peaceful. The dense energy within the space makes him wanted to just lay down and rest like a lazy panda.
"I guess you could say it's a copy of the Underworld without the demonic aspects. It's an entirely imaginary space I created with my own hands." With a wave of his hand, the grassy field shifted into a scorching desert. "I'm basically the creator of this realm. I can make anything I want."
"So… you're a fucking God? Huh? I don't even feel the pain I usually get when I say that!" Issei shouted in disbelief.
"I make the rules here, so physics is my bitch. Meaning, I can turn you into a rabbit if I really want to," Kousuke said casually, revealing just a taste of his Sacred Gear's true power. Inside this Imaginary Space, he could rewrite fundamental laws at will, but it cost him energy depending on how absurd the change was. He also discovered one limitation: he couldn't create living beings, as if the Sacred Gear itself wasn't made for that.
"But anyway, did you notice anything different about yourself?"
"What do you mean?"
[Buddy… this is insane. Your essence is basically that of a normal human now, but somehow you're stronger than before while still keeping your reincarnated devil traits.] Ddraig's voice rumbled in Issei's mind.
"Oh yeah, I can also separate Ddraig from you while keeping him linked to the Boosted Gear, basically giving him a physical body instead of forcing him to watch the world through your eyes," Kousuke added, casually dropping another bomb. This Sacred Gear was what made his VR project inch closer to reality. He hadn't tried something this complex on a living person before, so Issei was his first test subject. Of course, he wouldn't have attempted it without confidence.
Kousuke also noticed how seamlessly this Sacred Gear synergized with his Enchanter abilities. In theory, he could create an entire army of automatons under his command. Of course, the Sacred Gear wasn't absolute. People had their own wills and could resist him if strong enough. Otherwise it would be too broken, even for this world standard where nothing made sense. No, one thing did make sense, it's the fucking tits.