Because Darius could not accept the truth Jiang You had given him, he ultimately decided to activate the Technique to travel to the World in the Box.
With the cooperation of Jiang You and the others, Darius's plan went quite smoothly. Having quickly swapped places with the Giant King, he already saw the hole leading to the "New World." Jiang You also accompanied Illya into the Time Tunnel, following the original plot. Then...
"No, why have I turned into this thing!?" After crossing the Timeline, Illya found she had become a floating creature resembling a jellyfish, and she frantically slapped her own face.
"Simply put, it's because human bodies cannot travel through time. Your current state is more similar to a Fairy." Jiang You, who had replaced Tanaka, the Avatar of the Counter Force, explained to Illya. With his Authority, it was relatively easy for him to understand the sounds emitted by Illya's vocal cords, which now bore no resemblance to those of a human.
"Then why haven't you changed!!!" Seeing that Jiang You could still maintain a complete human form, Illya let out an extremely sharp, explosive shriek. "You're lying to me again, aren't you!"
"Don't be in such a hurry. There's a reason why you need to stay this way. Pandora, who is also Erika, clearly doesn't recognize me. Otherwise, she wouldn't have shown such a flustered expression back then." Furthermore, Pandora, whose personality had been corrected in the New Game Plus, was obviously influenced by Illya. Otherwise, she would never have reacted to those two inexplicable sentences. "So, you still have to play out the plot that should have happened. But don't worry, I have the ability to turn you back."
"That's more like it." Illya finally breathed a sigh of relief. Right now, she wasn't prepared to sacrifice everything.
Next, Illya did exactly what was shown in the manga Jiang You had given her. She found Pandora, who was all alone, delivered messages from the future, and comforted her loneliness.
Just like in the original Timeline, Illya's current form could not produce human sounds. As a being from the inner side of the World, she also couldn't leave written words in the Real World to communicate. In the end, the only thing she could convey was a pitiful yet mocking question: "Don't you have any friends?"
After spending a year together like this, the magical power Illya had manifested in Reality was completely exhausted, and she returned to the inner side of the World. Jiang You had wondered before why the Fairy Illya had turned into would disappear for a hundred years. It was simply the setting, but the reason hadn't been explained. Now he knew the cause. Jiang You could have renewed the magical power if he wanted to, but to avoid affecting the closed loop of events, he still didn't interfere.
As Fairy Illya returned to Jiang You's palm, he transformed her back into her human form.
"I'm absolutely exhausted." Illya, who had been in Fairy form all this time, let out a long sigh. Her Fairy body was really hard to get used to, and it was inconvenient for her to do anything. "Next time we meet will be in a hundred years... It was just two panels in the manga, but experiencing it myself feels so heavy..."
"Illya has worked very hard. Even without going through as many things as the original did, you were still willing to sacrifice yourself for your companion. That's why I like this Illya the most." Jiang You said words that would make the original Illya instantly explode, even though he meant them sincerely.
"Eek~ I'm definitely going to tell that other me!" Illya flailed her arms and legs, making a threatening sound. In truth, she wasn't very angry, because this was her destined fate; as long as she was Illya, she wouldn't make any other choice. But since Jiang You was truly willing to stay with her for such a long time, she really couldn't bring herself to hate him. "You unfaithful carrot."
"So it's all Illya, right? That doesn't count as being unfaithful." After everything they had been through, Jiang You had grown much thicker-skinned; there was no need to lie to himself anymore.
"Besides, it's not all bad news. Since the next hundred years have nothing to do with the key character Pandora, whatever we do here won't affect the closed loop of events. So, we have a lot of room to maneuver." Jiang You constructed a house, furnishing it like the small apartment Illya had back at the Einzbern residence. Then he turned on the TV. "Let's watch a movie. By the time it's over, a hundred years will have passed outside."
"Why didn't you say so sooner!" Illya threw herself onto Jiang You's head and started pummeling him in a rage. She had just finished mentally preparing herself for the wait!
The compressed six thousand years passed in a flash. Though they had skipped much of it, for Illya, it still felt like several years had gone by. For a ten-year-old elementary schooler (not counting the time she spent asleep), this already constituted a significant portion of her life.
"It should be today, right?" Illya, who was playing a video game, suddenly looked at the clock. She had long since grown impatient waiting out these six thousand years.
"You've already asked that a dozen times. Yes, it's today. I think it's about time." To avoid disrupting the alignment of the timelines, Jiang You hadn't taken Prisma Illya to other worldlines to spend this time. Here, they didn't need to wait for Miyu and the others to come rescue them like in the original story; they only needed to return to the time point of the exchange. Thus, Prisma Illya had been waiting impatiently. Jiang You was the only one who had accompanied her for these few years. They had said everything they had to say, and their relationship had advanced several steps. "Oh, it's already here."
This was a world that had already been destroyed. Theoretically, the only living beings were Jiang You and Illya, but at this moment, footsteps sounded outside the door.
"They're here, they're here!" Illya directly dropped the controller in her hand and opened the door in two steps. Outside the door was something composed of black mud that could barely be called a "person," but Illya didn't seem surprised in the slightest. She made a gesture of welcome to the black mud in front of her. "Welcome to the Einzbern Counseling Room!"
"Eh?" The black mud let out a sound of disbelief. "Who... are you?"
Darius felt as if he had endured an incredibly long journey. He had finally arrived in the World in the Box he had so long desired. All its unknown mysteries would belong to him, and he would become the god of this New World. Or so it should have been. But after the endless darkness, he saw a cozy house, its windows radiating a soft glow.
"It seems you've developed dementia from all that time," Illya said, shaking her head in frustration. After such a long wait and understanding Darius's original intentions, her hatred for him had mostly faded, replaced by a sense of pity and sorrow. Though, because Jiang You had intervened, she hadn't suffered much and never harbored much hatred to begin with. "But we still remember you, Mr. Darius Ainsworth."
Upon regaining his True Name, Darius also regained his original appearance, the face of his younger self.
"I've already told you, the Box has been opened once before. If you don't believe me, there's nothing I can do." Jiang You stepped out at that moment, wearing an apron and looking like a devoted husband at home. "Anyway, welcome to the World in the Box you so desired. The timing is perfect. How about dinner? Come taste my six thousand years of culinary skill."
"Actually, it's only two and a half years of skill," Illya directly exposed Jiang You's lie.