"Where should I start?" Selena asked softly, her smile never leaving her face.
The scene had changed in an instant. Instead of the cold gleam of the crystal throne room, they now sat around a round tea table in a lush rooftop garden. Selena had teleported them here with a wave of her hand, remarking that "standing around in the throne room isn't really relaxing, is it?"
The garden was breathtaking. A round table, set with tea and sweets, sat at the centre of the garden. Around it, vibrant flowers bloomed in every shade imaginable; some were even glowing faintly in the dark. It was unlike anything Akira had ever seen before. For the first time since entering the castle, he could finally see the sky outside.
It was night. A vast sea of stars stretched endlessly above them, shining brighter than anything he had ever seen on Earth. Akira frowned. He was sure it had been morning when he stepped into the castle. Did time flow differently here? Or was this a place of eternal night?
Akira drifted into thought, but Selena's teasing voice pulled him back.
"Please don't enter another flashback, brother," she said with a smirk.
Akira blinked, catching himself. "Sorry, I was just… absent-minded. What did you say again?"
"I asked," Selena repeated patiently, "where should I start?"
"From the beginning," he answered without much thought.
Her expression grew serious, and her tone softened with weight.
"In the beginning… There was nothing. And then…"
"Whoa, whoa, wait!" Akira interrupted, raising both hands. "You don't have to go that far back! I was asking about us, not the creation of the universe!"
Selena giggled. "But the beginning of everything is directly connected to our backstory. It's important."
Akira sighed. "Fine. Continue."
Selena nodded and continued, "A young shoot sprouted from the cracks of primordial chaos. Nurtured by time for billions of years, it grew into a huge, unrivaled tree, the Imaginary Tree."
Akira leaned back, muttering, "Like Honkai Impact 3rd?"
Selena smiled knowingly. "Yes. But also a little different. I'll explain later."
Erika tilted her head, puzzled. "What's Honkai Impact 3rd?" She didn't ask, deciding it was probably just another anime or game Akira liked.
Selena's voice flowed on.
"The Imaginary Tree contains all of existence. Its branches represent different possible timelines and worlds across the multiverse. Its leaves symbolize the present state of those worlds. The Tree absorbs energy, grows, and gives birth to new universes."
Erika's eyes widened. "So… there really are other worlds? Does the multiverse actually exist?"
"Yes," Selena confirmed. "Everything exists in the Imaginary Tree, all possibilities, as well as all of reality, with every possible choice and outcome; the imaginary tree contains all of it."
"What does that even mean?" Erika pressed, for her, this whole thing is a little overwhelming.
Selena rested her chin on her hand and smiled, thinking of how to explain it easily. "Think of it like this: a visual novel with multiple routes."
Akira perked up immediately. "Like Fate/Stay Night?"
Her lips curved into a smile. "Yes. That world exists in the Tree as well. And not just one version, all three routes also exist as separate realities. Not just that every possibility a player chooses, every different outcome of that story… also becomes exist."
Akira blinked. "…So you're saying the Imaginary Tree literally contains everything?"
"Everything," Selena confirmed, her voice calm and absolute. "For example, if someone wrote a new story right this moment, that world could already exist within the Tree too."
Akira tilted his head, his mind racing. "Wait. So… does that mean everything is canon?"
Selena giggled softly, covering her mouth with her hand. "Yes. Not just every route is canon. Even a fanfiction someone scribbles on a whim it exists too. All of it."
Akira sat back, stunned for only a moment. Then he gave a wry smile.
Akira accepted it without hesitation; after all, he was literally sitting in an anime-like world already. His eyes glimmered in excitement. "So… does that mean we can travel to those other worlds too?"
Selena only smiled at her brother's eager question, shaking her head slightly.
"I'll explain about that later. For now, let me finish our family's backstory first."
Akira leaned back in his chair, still unable to hide the sparkle of excitement in his eyes. "Alright, alright. Go on."
Selena's cheerful air softened, and for the first time since they sat down, her tone carried true gravity.
"The Imaginary Tree was not alone. Though vast and eternal, it had a rival… or perhaps an enemy."
"Wait, don't tell me. Is it the Sea of Quanta?" Akira said with interest, thinking it would be similar to Honkai Impact 3rd.
But Selena slowly shook her head, her smile fading into something quieter.
"No. Not the Sea of Quanta. That is something else entirely, something much more terrifying, it's called the Sea of Nihility."