"Big brother is weird."
I looked up from the coral sculpture I'd been pretending to play with. A tiny mermaid with pink hair and big eyes was staring at me from across the nursery. My little sister, Shirahoshi, who was about three months old now.
Wait. She could talk already?
"Shira, you shouldn't say that," Mira chided gently, though she was smiling.
"But he is! He just stares at things. Doesn't play normal."
I wanted to argue, but she kind of had a point. Most toddlers weren't running genetic simulations in their heads during playtime.
I crawled over to her - yeah, I could walk, but crawling seemed more age-appropriate sometimes. "Not weird. Just busy."
Shirahoshi giggled. It was actually pretty cute. "Busy doing what? You're a baby."
"Thinking."
"About what?"
How to explain genetic engineering to a three-month-old? "Um. About making everyone happy."
Her eyes went wide. "Really? That's nice! I want everyone to be happy too!"
Great, now I felt bad. She was so innocent, so genuine. In the original timeline, she'd grow up traumatized and afraid, locked in a tower for years because of death threats.
Not this time. I'd make damn sure of it.
"We'll do it together," I told her. "When we're bigger."
She beamed at that and reached out to hold my hand. Her grip was surprisingly strong for a baby mermaid.
The nursery door opened and three more kids swam in - well, they were being carried by attendants. My younger brothers. Fukaboshi, Ryuboshi, and Manboshi, triplets who were just a few weeks old.
The nursery was getting crowded.
Fukaboshi was the calmest of the three, just looking around with curious eyes. Ryuboshi kept trying to wriggle out of his attendant's arms. Manboshi was already asleep.
"Prince Arquen, would you like to meet your brothers properly?" one of the attendants asked.
I nodded and crawled over. Being the oldest suddenly felt real. These were kids I'd need to protect, to guide. No pressure.
Fukaboshi looked at me and made a little sound, reaching out. I let him grab my finger.
"Strong grip," I muttered.
"He'll be a warrior like his father," the attendant said proudly.
Maybe. Or maybe he'd be something else entirely if I had anything to say about it.
The next few months fell into a weird routine. Mornings were for "playing" which really meant me running more mental simulations while pretending to stack blocks. Afternoons were family time, which actually wasn't bad. Otohime would tell us stories, Neptune would visit when he could, and my siblings were growing on me.
Shirahoshi followed me everywhere. She'd decided I was her favorite brother, which was sweet but also meant I had zero privacy.
"What are you looking at?" she asked one day when she caught me staring at a guard.
"Just watching."
"Why?"
"Learning."
"Learning what?"
Kids and their endless questions. "How people move. How they act."
She tilted her head. "That's boring. Wanna play hide and seek instead?"
"Can't. Too small." I was only one and a half now, and the palace was huge. I'd get lost.
"I'll help you hide!"
Before I could argue, she'd grabbed my hand and pulled me behind a large coral formation. Her tail swishing excitedly.
"Shira, we shouldn't—"
"Shh! Mira's gonna look for us!"
I sighed but went along with it. Being a good older brother meant sometimes doing dumb kid stuff, I guess.
We sat there in silence for a bit. Well, Shirahoshi tried to be silent but kept giggling.
"Arquen?" she whispered.
"Yeah?"
"Do you think humans are scary?"
The question caught me off guard. "Why do you ask?"
"I heard some guards talking. They said humans are mean to fishmen. That they take people away sometimes."
Slavery. She was talking about slavery, even if she didn't know the word.
I thought carefully about my answer. "Some humans are mean. But not all of them. Just like some fishmen are mean, but not all."
"Mother says we should be friends with humans."
"She's right."
"But if they're mean—"
"Then we get strong enough that they can't be mean anymore," I said simply. "We protect ourselves and the people we care about."
Shirahoshi looked at me with those big eyes. "You're gonna protect us?"
"Yeah. I am."
She smiled and hugged me, almost knocking me over. "You're the best big brother!"
I patted her head awkwardly. Emotional moments were still weird for me.
"Found you!" Mira's voice called out. "You two are terrible at hiding."
Shirahoshi giggled and swam out. I followed, but my mind was elsewhere.
That night, I went back into the mental simulation. I'd been working on a basic formula for weeks now. Nothing fancy, just something that could enhance the natural abilities fishmen already had.
The problem was stability. Every time I tried to add too many modifications, the simulated genetic structure would collapse. It was like building a house of cards - one wrong move and everything fell apart.
I needed a binding agent. Something that could hold the modifications together without rejecting the base genetics.
My own DNA was the obvious answer, but I couldn't exactly extract samples from myself yet. I was a toddler. Nobody was letting me near medical equipment.
Unless...
I focused on my Adaptive Biology trait. If I could analyze others through touch, could I analyze myself internally?
I turned my analysis inward, and suddenly I could see my own genetic structure. It was way more complex than a normal fishman's. The Poseidon-class evolution had added layers and layers of additional sequences.
But there, buried in the complexity, was something interesting. A specific marker that seemed to act like glue, connecting all the different modifications seamlessly.
That was it. That was the binding agent I needed.
Now I just had to figure out how to replicate it synthetically.
I spent hours in the simulation, breaking down that marker, understanding how it worked. My comprehension ability was going crazy, making connections faster than I could keep up with.
By the time I exited the simulation, the sun was coming up.
[Milestone Progress: 15%]
[Note: Exceptional progress for current age and resources]
Fifteen percent wasn't much, but it was something. And I still had over three years before the time limit.
Mira found me yawning at breakfast.
"Late night, Prince Arquen?"
"Couldn't sleep," I mumbled. Which was technically true.
"Growing pains, probably. You're getting so big!"
If she only knew what was really keeping me up.
Otohime came by after breakfast. She did that more often now that there were more kids. Making sure we all got individual attention.
"How's my little thinker today?" she asked, picking me up.
"Tired."
She laughed. "Thinking too hard?"
"Maybe."
She carried me to a window that looked out over the Fishman District. You could see the curved streets, the buildings made of coral and stone, the fishmen going about their daily lives.
"Someday, you'll help lead these people," Otohime said softly. "Do you understand that?"
I nodded.
"It's a big responsibility. But I think you'll be wonderful at it." She looked at me with such warmth. "You have a good heart, Arquen. Don't ever lose that."
"I won't," I promised.
And I meant it. Whatever power I gained, whatever changes I made, I'd keep that at the core.
Because in the end, that's what would make the difference between a tyrant and a true leader.