The underground training facility was silent except for the hum of ventilation and the faint dripping of condensation from the ceiling. The air was cool, almost sterile, but not uncomfortable. I stood in the center of the reinforced training hall, rolling my shoulders as my grandfather, Sang-hoon Lee, observed me with his usual calculating gaze.
"Go start your warm-up, kid," he said, his voice carrying that rough edge of a man who had seen far too much battle.
I nodded and began my routine. Warming up wasn't just about avoiding injuries—it was about preparing my body for the sheer strain I was about to put it through. I started with dynamic stretches, rolling my neck from side to side before loosening my shoulders. Arm circles, forward and backward, followed by wrist and ankle rotations. Every joint had to be primed for movement.
Next, I transitioned into mobility drills—leg swings to loosen my hips, lunges with torso twists to open up my core, and deep squats to activate my legs. My muscles began to warm, my blood circulating faster. After that, I moved into high knees and butt kicks, increasing my heart rate gradually. The final part of my warm-up was explosive movements—burpees, quick sprints, and broad jumps. By the time I was done, a thin layer of sweat coated my skin, my body thrumming with readiness.
"Good. Now, weighted calisthenics," my grandfather ordered, tossing a set of weighted straps toward me.
I secured them around my wrists, ankles, and torso—a total of twenty kilograms distributed evenly across my body. The extra weight made every movement deliberate, every push and pull a challenge. I dropped to the ground and started my push-ups, my muscles already adjusting to the increased strain.
One. Two. Three. Each repetition burned, but I pushed through.
"Come on, kid! You call that a push-up? Put your back into it! Your father's going to be ashamed if you keep that up!" Grandfather's voice echoed through the hall.
I grit my teeth and increased my pace. Ten. Fifteen. By twenty, my arms trembled slightly, but I forced myself to hold proper form.
"That's more like it! Don't train half-assed if you want to get stronger!"
Before I could catch my breath, he barked out the next instruction. "Handstand. Ten minutes. Now."
I exhaled sharply and kicked up into a handstand. The weights made balancing significantly harder, my shoulders burning as I held myself steady. Gravity worked against me, my arms straining to keep me upright.
"Keep your core tight! Don't let your body shake, or you'll collapse like a damn rookie!"
Minutes crawled by, my vision blurring slightly from the blood rushing to my head. I focused on my breathing, keeping it steady. Finally, the ten-minute mark arrived, and I lowered myself carefully.
I barely had time to shake out my arms before he ordered, "Plank. Twenty minutes."
My stomach tensed as I dropped into the plank position. The pressure built up quickly, my entire core working to hold steady. Fatigue settled in, my limbs shaking slightly, but I embraced the burn. It wasn't the kind of pain that signaled damage—it was the pain of growth.
When I finally collapsed, my breath came in short gasps. Grandfather handed me a water bottle and nodded approvingly. "You're doing good, Rheon. This kind of stress will mold you, make you stronger. You need a body that can handle the strain of your Cryokinesis. The stronger you are, the better your control will be."
I wiped the sweat from my forehead and smirked, despite my exhaustion. "I feel miserable."
Grandfather raised an eyebrow, and I grinned. "Kidding. It hurts like hell, but my body's getting used to it. Strengthening, improving."
He let out a rough chuckle. "That's the spirit. Five-minute break. Then we move on."
After my break, I jumped straight into explosive power drills. First, box jumps—I started at a standard height, then gradually increased the difficulty. Each leap required explosive power from my legs, my thighs burning as I pushed myself higher and higher. Then came the sledgehammer swings. I gripped the heavy hammer, lifted it over my shoulder, and brought it crashing down onto a thick rubber tire. Every strike sent vibrations through my arms, strengthening my grip and endurance. Finally, medicine ball slams. I hoisted the weighted ball over my head and slammed it onto the ground repeatedly, engaging my entire body in each movement.
By the end of the set, I was drenched in sweat, my breath heavy. I sprawled on the floor, staring at the ceiling, trying to catch my breath.
"Good job, Rheon," Grandfather said, throwing a towel over me. "Go have your lunch. Be back by 1 PM."
I didn't cool my body down. Instead, I let it acclimate to the stress as Grandfather had advised. After a few minutes, I took a quick shower, changed into a black hoodie jacket, brown cargo pants, and white sneakers, then strapped my Rolex onto my wrist before heading to the canteen.
It had been seven years since my proclamation as heir. Now, at fifteen, a lot had changed. Subin and Jisuk were now seven, though they never really got along despite their mothers arranging playdates. Jiwoo was likely still with his mom, and Woo In was under Dr. Delein's care. Jiyoung had awakened at seven—three years earlier than the standard age, a rare feat, though not as rare as mine. Still, it was a moment of pride for the Yoo family.
As I entered the canteen, familiar voices called out. "Rheon-nim, are you eating here? Come sit with us!"
I had grown familiar with the Union agents and staff. Unlike some heirs, I wasn't distant. I sat and ate with them, listening to their conversations, laughing at their jokes. They respected me for it.
After eating, I made my way to the rooftop. The view was incredible—Seoul stretched endlessly before me, the skyline blending into the horizon. The wind was crisp against my face, a quiet reprieve before training resumed.
As 1 PM approached, I sighed and headed back underground, my body already bracing for what was to come.
Grandfather wasted no time. "Control and efficiency training. First, condensation manipulation. Draw moisture from the air, create ice without an external source."
I exhaled slowly, my Cryokinesis activating. Midnight blue ice—darker than the usual crystalline blue—began to form. Next, temperature regulation. I lowered the temperature in the room, maintaining it steadily. Then, precision training—ice sculpting. I carved intricate designs, refining my control.
Next was combat training. I formed an ice armor, ensuring it didn't restrict movement. Grandfather fired ice spikes at me, testing my defense. I activated Cryo-Adaptive Muscles, lowering muscle temperature to extend exertion time, and then Hydraulic Ice Compression, freezing water within my muscles to amplify strength. My punches and kicks struck the training dummy repeatedly.
The first punch cracked through the air. I followed with another, then another—each one sharper, heavier, faster. I transitioned into kicks, utilizing my entire body. My knee connected, then my elbow—everything was a weapon
When the alarm rang, signaling the end, I collapsed onto the floor, exhausted. Grandfather handed me another towel. "Good job, Rheon. I'm proud of you."
I smiled, only for a small figure to burst in. "Big brother! I was waiting for you!" Subin pouted.
I sighed, rubbing my head. "I had training, Subin. But tomorrow, I promise we'll play."
Grandfather cooed at her. "Subin, it's your grandpa!"
She only glared. "Bad Grandpa! Big brother can't play because of you!"
Mother arrived, looking worried. I reassured her I was fine while Grandfather—the mighty Sang-hoon Lee—apologized to his granddaughter.
I chuckled softly, realizing how precious these moments were. No matter what, I would protect them.