Time passed quietly.
During this period, Yu Zhou had been accompanying the Earth Defence Force's team, helping them search for the source of darkness.
At Cain's earnest request, Yu Zhou even taught him a few techniques for controlling and releasing energy—significantly improving the young man's combat ability.
Meanwhile, Captain Yuzare often brought Yu Zhou food herself.
That… caused quite a stir among the younger members of the defence team.
Yuzare wasn't just anyone—
She was the commander of the Earth Defence Force, and the princess of the entire continent!
And yet she was personally delivering meals to a man of unknown origin?!
Even if he was said to be a friend of the princess and Prince Cain, there had to be a limit!
"Unbelievable! I'm going to challenge that guy to a duel!"
One hot-headed young soldier shouted, storming toward the ship's exit.
"Hey, calm down, man!"
"Don't be rash!"
"Bro, you can't go like this!"
His comrades rushed to stop him.
"Let me go! I'll fight him right now!"
But when the man was about to shove his way through the door, his teammates surrounded him.
"Hold up, bro—before you go anywhere, could you maybe… put some clothes on?" one said helplessly.
"Yeah, seriously. At least wear pants if you're gonna pick a fight."
"Exactly! You can't just show up naked; people will get the wrong idea about what kind of fight you're looking for."
"Right! They'll think it's… a different kind of duel."
The man blinked, then slowly looked down at himself.
Oh. He was stark naked.
"…Never mind then. I was sleepwalking. Forget everything."
He promptly turned around, climbed back into bed, and fell asleep.
Everyone else just stared at him in silence.
Yu Zhou, of course, had no idea that someone had almost come to "duel" him—and even less of an idea what kind of misunderstanding that duel might've been.
At the moment, he was lying on his bed while Yuzare sat quietly at its edge.
"You came to my room this late," Yu Zhou asked, sitting up slightly, "something important must've happened?"
Unlike her usual armoured self during the day, Yuzare now wore a simple white gauze dress. The cold, commanding air she usually carried was gone, replaced by a soft, stunning beauty that could topple nations.
"Tiga, I…"
She hesitated, her cheeks faintly flushed as she met Yu Zhou's eyes.
"You?" Yu Zhou tilted his head, confused. "Don't tell me you came here for that reason."
"You… you already knew?" she murmured, voice barely louder than a mosquito's buzz, clearly embarrassed.
Outside the door, Cain—who happened to be eavesdropping—froze.
That reason?!
What reason?!
Wait… no way!
His mind raced. His imagination filled in every possible "that kind of thing" scenario.
He clenched his fists. Unacceptable!
That was his sister in there! His sister—and his teacher!
He couldn't just stand there and let such an indecent thing happen right outside his earshot!
"I have to stop them!" he whispered furiously.
Inside the room…
Yu Zhou and Yuzare locked eyes, neither blinking.
"You've been bringing me food every day," Yu Zhou said calmly, a small smile tugging at his lips. "I don't believe that's something a princess would do without a reason. Just tell me what you want."
"Let me guess… You're after knowledge about manipulating light and dark energy—or maybe you want the formula for the Light Particle Converter."
"You even knew that…" Yuzare's face turned redder.
She had intended to subtly bring up the topic, but now that he'd seen right through her, she couldn't help but feel flustered.
Just then, there was a loud bang! from the door, followed by a thud.
"Huh?"
Frowning, Yuzare walked over and opened the door.
"Cain? Why are you lying on the floor?"
"Ahahaha… The floor's cool. Very refreshing!" Cain replied with an awkward laugh, rubbing his forehead.
He had been all set to kick the door open dramatically, but as soon as he overheard that they weren't doing what he thought they were doing… he'd tried to stop himself mid-charge. Too late. The door had stopped him instead.
"What were you even trying to do?" Yu Zhou asked as he stepped over. "The door wasn't locked—you could've just opened it."
Cain had no words.
Yu Zhou sighed and continued, "I was just about to step outside for some air. Who knew you two siblings both liked visiting people in the middle of the night?
"And to make it worse, your sister closed the door behind her! Nearly roasted me alive in here."
He stepped out onto the deck, letting the cool sea breeze wash over him.
Cain twitched when he heard the word 'siblings.'
"'Siblings?'" he echoed quietly, looking conflicted—but ultimately decided not to correct him. Given what had just happened, the less said, the better.
Yu Zhou, unaware of the awkward subtext, continued like a proper teacher now.
"Cain, as Yuzare's younger sister, you really should learn from her composure. You're far too impulsive. You'll inherit your father's position one day—you need to learn how to govern the continent calmly."
"…That sounds exactly like something my father would say," Cain muttered in defeat.
It seemed no matter who lectured him, he was always the same kind of person in everyone's eyes.
"Anyway," Yu Zhou said, turning back to Yuzare, "where were we again?"
"The Light Particle Converter," she reminded him.
"Ah, right."
Yu Zhou sat back down and folded his arms thoughtfully.
"To become a giant of light—or a giant of darkness—you need a particle converter," he began.
"For the giant of light, the converter must be able to transform a human body into pure light particles."
He paused before continuing in a more serious tone.
"But there's something else… something I don't fully understand yet. Based on past experiments, it seems that to transform completely, one also needs the physical body of a giant—essentially, a giant's stone statue."
He looked at both Yuzare and Cain solemnly.
"This means that while the converter allows a person's essence to change into light, the statue serves as the vessel—the fighting body—for that light to inhabit."
Yuzare and Cain listened closely, their expressions grave.
What Yu Zhou was describing wasn't just theory—it was hope.
Knowledge that could determine the future of humankind.