On the fifth day, Rossweisse was already haggard but she was not willing to give up the 500-Yen shop and persevered. Eventually, the two of them finished the model after numerous final adjustments, simulations, and real-world testing.
Rossweisse sat down and took a breather, "What do we do next? Where do we lay this absolutely massive thing?" She thought with the amount of encryption and security they added to the spell itself, they would have no problem even with people watching and recording everything they were doing.
Using his arm as the key once again, Kisuke opened a portal back to Earth, "Everything is already prepared. We just have to finish this within two days."
Rossweisse never really thought that it would be possible to finish this entire thing within a week but she was already proven wrong with all the progress they made which she thought would take a month or two. Rossweisse stood up and followed Kisuke to the other side of the portal while saying, "I'm still really curious as to what you're going to use to power this thing."
The moment Rossweisse stepped out, the cold temperature immediately greeted her, and soon the wasteland and out of place large stacks of freight containers all around them, "Where are we?"
"Devon Island. I arranged the spell to fit this place perfectly." Kisuke then looked around and smirked, "My~ Looks like we have quite an audience."
Although not as much as Kisuke's, Rossweisse's senses also caught a few people from beyond the island watching them, 'They are... From various Mythos...'
"It's impossible to hide the fact that I took over this island so they are probably curious about what we're doing here." Kisuke then took out Benihime in her Shikai, "Oh well, after we're finished, it should give them a bit of a scare so they finally do something, so this is good."
Swinging Benihime diagonally, Kisuke sent out a shockwave that carved out the earth, "The materials are inside those containers and I'll leave the filling to you."
Rossweisse opened one of the containers and saw various things inside of it, "...I don't know some of these."
Kisuke ramped up his work while answering, "Just test their Magic conductivity and you should be good. You can also call for people to help you melt and move those."
"...You're not going to reduce my pay if I do that, right?"
Kisuke froze for a moment and thought that she really has an incredibly very bad view of things in terms of employment, "No. I'll prepare a separate reward for those who want to work part-time. Just make sure that you properly overlook their work."
.
.
.
For the next two days, onlookers continued to gather and for the first few hours, there were a few brave souls that tried to approach and intrude on the island in hopes of gathering more information on what they were trying to achieve.
At first, Kisuke ignored them since there was really nothing they could gather from it and it was not worth the effort to keep them out. But when they started messing with the canals he dug, that's when he went ballistic and chopped off a few limbs of these intruders. Others tried to help this group and 'reason' with Kisuke but he didn't listen and just did the same thing to them. Chopped their limbs until they were left crying.
Since it would be troublesome to keep doing this, Kisuke dedicated a few hours to hunting these intruders and chopping their limbs off for the sole reason of stepping onto Devon Island.
Of course, there were protests about how he does things but he ignored them since the chopped limbs were still restorable, so what they were saying doesn't have much weight.
Unsurprisingly, there are some people who thought of taking advantage of this. Since Kisuke was only aiming for their limbs, they presumed that they'd be able to catch him off guard. But the moment they showed their killing intent, Kisuke's blade changed its trajectory and severed their heads.
From then on, no one thought of bothering them anymore. Though some of them still went to the Alliance to try and shut down whatever Kisuke was doing while citing that his construction was a massive breach of security to everyone.
But with Issei, a few of his crew, and a few of Vali's crew helping out Rossweisse, that didn't gain any traction.
And just like that, they were able to finish the massive Magic Circle that spanned the 5.5 million hectares of land.
Kisuke returned to where everyone was while looking at the time, "Thank you, everyone~. I finished a few hours earlier than I expected."
"Just a few hours? Even with all of us?" Issei asked while pointing at everyone, namely, Ravel, Ingvild, Arthur, Le Fay, and Sha Wujing.
Kisuke scratched his head and confessed, "I actually took it a bit easy when you arrived~"
'Took it easy!?' They all exclaimed internally since Kisuke did 70% of the work despite them helping out.
"Anyways, we still have a few hours before the 'core' arrives. How did it go on your side?"
At that question, Issei and the rest, except for Rossweisse, had a heavy expressions, "We had cleaned up a number of them... But then an Evie known as Rugatimu also revealed himself." Issei replied. He'd already heard the secret about the 'future' from Azazel and Sirzechs, but he didn't want to talk about it publically.
"Rugatimu is a five meters tall humanoid mechanical lifeform with three eyes possessing a tremendous aura that dwarfs most of the Chief Gods." Le Fay added with a somber expression.
"And the problem is?"
Issei sighed before answering, "I teamed up with Vali and we were no match against him even in our full power. In fact, he only retreated because he didn't want any more trouble arriving. According to Ajuka-san, Azazel-sensei, and Sirzechs-san, he might be on par with Great Red or Ophis at their peak."
But when he looked at Kisuke again, he didn't seem to be too concerned and smiled in relief, "This barrier can keep them away, can't it?"
Kisuke nodded, "Of course. It would really be convenient if this could trap that guy, but I doubt that since it'd take a minute or two before this can be activated in its entirety and anyone competent would be able to escape and they would choose to do so."
"Because it's just their scouting force, is it?"
"That's correct. And there's-... Hmmm!?" Kisuke was about to reveal that there was someone else much stronger than the one they encountered when the automatic Teleportation Magic suddenly began activating ahead of its schedule, "Rossweisse-san, prepare for the linking of the core! Issei and the rest, leave the island immediately and stop anyone that comes close!"
"What? But where's the core? And what type of power source is it?" Rossweisse flew towards her designated Magic Circles while communicating with Kisuke with Magic.
"It's delivering itself. And don't worry about the process. I'll take the lead and you just have to follow it... And steel your heart because I'll be needing your concentration more than ever."
Rossweisse became confused by his last words but didn't have time to think about it when she saw a 100-meter Magic Circle appearing on top of where the core should be, 'A Teleportation circle? So that's what he meant by delivery... But why did he word it so weird...ly...'
Rossweisse's thoughts trailed off until nothing was left as a massive amount of blood started spilling from the Magic Circle and dropping to the ground. Soon, an almost 100-meter body of a red headless Dragon dropped from the circle before it was followed by its detached head with lifeless eyes wide open.
The core of the barrier had revealed itself and it was far from everyone's expectations. The lifeless body of one of the greatest existences of this world, Great Red.