The Second Life of Demon King

Episode 5: First Experiments with Mana

Two years old. Isaac’s hair had grown thicker now, jet-black curls falling messily across his forehead. His eyes were sharp—too sharp for a toddler. Behind those round, innocent-looking eyes, a storm blazed. And this morning, that storm decided to move.

"Today… we begin," Isaac whispered, sitting cross-legged on the carpet of his bedroom.

The room was silent. Only the ticking of an old wall clock and the chirping of birds outside the window could be heard. Sunlight reflected softly off the wooden floor, making the atmosphere feel warm and calm—too calm for what was actually happening.

"Focus. Breathe in. Feel… the mana."

He closed his eyes, calming his thoughts. But inside, his brain worked like a war machine. He visualized the mana pathways, scanning his body from head to toe. He was trying to sense that vibration again—the one that had nearly made him faint the day before.

"Mana isn’t just power. It’s about will. And I’ve mastered it once… in another life. There’s no way I’ll fail in this body," he thought, his teeth clenched.

But the human body… was weak.

His hands trembled. His heartbeat sped up. It was as if his body instinctively knew it was doing something no toddler should attempt.

"Ngh… don’t give up. This is just… an early limitation."

He adjusted his breathing pattern. Deep inhale. Hold. Exhale. Repeat. Again and again. Slowly, the air around him shifted. The room’s temperature dropped a few degrees. The curtains swayed gently. In the palm of his tiny hand, a faint glow appeared—for just a second. Very small. But real.

"Ha! I knew I could do it!" Isaac's eyes widened, thrilled.

But his body didn’t agree.

In a flash, the glow vanished. And his body collapsed.

Isaac coughed harshly, his body trembling, sweat pouring down his forehead.

"Damn… too fast," he thought. "This body… isn’t ready. But I did it. I saw it. I touched it. Mana is real."

He tried to get up, but his entire body felt like it had been struck by a hammer. Weakness spread through him—even his eyelids felt heavy. He crawled to the bed, dragging the blanket over himself with the last of his strength.

"Isaac?" came the gentle voice of his nanny from outside the door. "Are you awake yet?"

He quickly shut his eyes.

The door opened. Light footsteps approached. The scent of soap and toasted bread filled the air.

"Still asleep, huh?" she whispered, gently stroking his head. "It’s so cold this morning. You probably need more sleep."

Internally, Isaac sighed in relief, but he kept his eyes tightly shut. He couldn’t be found out. Not yet.

A few hours later, after she had left, Isaac opened his eyes, staring at the ceiling.

"This body… still too weak. But I’ll make it strong. Even if I have to crawl for years."

He glanced at his small hand. A human hand. But now… one that held potential.

Weeks passed—

"One… two… three… hold your breath…" Isaac curled up in the corner of a storage room behind the kitchen.

It was cramped, damp, and smelled of old wood. But no one disturbed him here. He could practice without being seen by the maids.

He sat cross-legged, hands on knees, eyes closed. Now, he no longer tried to summon light. He focused only on control.

"Feel it. Don’t force it. Listen to the pulse. Like the current of a river. Mana… flows."

Slowly. Gently. Almost imperceptibly. But each day, he could feel it faster. He’d even begun to summon a faint heat at his fingertips.

"If I can strengthen this path… I can form patterns. And if I can form patterns, I can cast basic spells."

Suddenly, footsteps echoed outside the storage room.

"Huh? Why’s this door open?"

Isaac’s eyes shot open. That was a maid’s voice! He flattened himself to the floor, holding his breath.

"Must’ve been mice again…" the maid muttered before closing the door.

Isaac exhaled long and slow. "That was close."

Though exhausted, a smile crept onto his face.

"This world… has different rules. But I’ll rule here too. Not by blood—but by hard work."

As the sun set, he returned to his room. Sat on the bed, hand on his chest.

"We start from here… But one day, they’ll all know. This world will know. Isaac Ackerman… is no ordinary toddler."

And then, he smiled faintly.

"And please, God… don’t let anyone think I’m possessed."

Outside the window, the night hung quiet. Unaware that in that small room, a former demon king was training a new power.

Not for revenge. But to conquer the world again—through a completely different path.

A year had passed. Morning light slipped through the cracks of a large window draped in lace curtains. On a small bed adorned with wooden carvings, Isaac—now two years old—curled under a pale blue blanket. His round eyes blinked open slowly, staring at the star-painted ceiling. He let out a wide yawn and stretched like a newly hatched chick.

“Isaac, wake up, sweetheart. It’s morning,” Lady Evelyn’s gentle voice came from the doorway.

Isaac stretched once more, then sat up with a confused expression and messy hair.

“Hmm? Mama?” he mumbled, slipping a finger into his mouth like a groggy toddler.

But in his mind...

“Five seconds slower than scheduled. That maid poured the water too late. Her efficiency has dropped since yesterday evening. Is she sick?”

Evelyn walked in and picked him up from the bed, hugging him tightly. “Today you’re going to learn about colors, okay?”

Isaac tilted his head, then gave a sweet smile. “Red… that’s like blood, right, Mama?”

Evelyn paused. “Uh… well, that’s… one way to look at it.”

In the corner of the room, the young maid carrying the breakfast tray choked slightly.

Isaac giggled. “Hehe, I’m joking!”

“Their reaction patterns are slow. Hm. If I can master this expression better, no one would suspect a thing even if I summoned a demon from beneath this wooden floor.”

After breakfast, Evelyn carried Isaac to the back garden. The sun was climbing, and dew still clung to the leaves. The garden was neatly arranged, with a stone path winding through the flowers.

“Look, a butterfly! Isn’t it cute?” Evelyn pointed at a yellow-winged creature dancing in the air.

Isaac stared at it.

A weak creature, defenseless. But beautiful… Intriguing. This world is full of revolting contradictions.

“It’s cute, Mama. But if I hit it, it could die, right?”

“Isaac…”

“No, no, I don’t wanna kill it! I love butterflies,” he quickly added, slapping his own cheek. “Isaac is bad, huh?”

Evelyn hugged him and kissed his head gently. “No, you’re just curious.”

Curious? No, this is calculation. But fine, call it curiosity. It’s easier.

At night, when the Ackerman estate fell into silence, Isaac slipped out of bed. His small footsteps were nearly soundless on the wooden floor. A gentle night breeze came through a slightly open window, bringing the scent of wet earth and rosemary from the garden.

Isaac sat cross-legged on the floor, his tiny body upright, no longer bearing the look of innocence, but rather a calm lethality.

He closed his eyes.

Feel it. Don’t force it. Let the mana dance...

Suddenly, the window shook from the wind, and the curtain brushed his cheek.

Isaac opened one eye. “Damn. I forgot to lock the window.”

He got up, shut it tight, and sat again.

Sweat ran down his temple. His human body was weak, limited. But he was learning—every night he cursed this weakness, and every morning he forgave it with a sweet smile.

Outside his door, the old maid Greta paused, hearing faint murmurs inside.

“Eh… probably just the boy dreaming and wetting the bed,” she muttered, walking off.

Isaac smirked.

Everyone in this house is predictable. They live in dull patterns. But I must be cautious. Advancing too quickly will raise suspicion.

Outside, the hoot of an owl filled the silence. Isaac took a deep breath, trying to blend with the rhythm of the night. His hand rose slowly, then clenched.

A thin blue light flowed between his fingers. Faint, almost invisible—but enough to make him grin.

“Significant progress… But still not enough to kill anyone,” he whispered.

Then—footsteps. Fast, light.

Isaac dove back into bed, pulled the blanket over himself, and hugged the ugly dog plush his cousin gave him last week.

Evelyn peeked in.

“Isaac?” Her voice was soft.

The little boy squirmed and mumbled, “Wanna dream of flying horses…”

Evelyn smiled and gently closed the door.

As her footsteps faded, Isaac opened one eye again and murmured, “Flying horses are a myth, Mama. But a five-winged snake-headed creature… I used to keep one as a pet.”

The next morning, Isaac was seen playing with colorful blocks, making strange sounds with his mouth.

“Vroom… boom! Building’s down!” he shouted, knocking over a freshly built tower.

Duke Reinhardt passed by and chuckled. “Son, you’re a genius at destroying rather than building.”

Isaac turned and stuck out his tongue. “I’m a kid, Papa. I can!”

“Fair enough.” Reinhardt ruffled Isaac’s hair and walked off.

If only you knew. You wouldn’t dare touch my head so casually.

Isaac returned to stacking the blocks. His hand trembled slightly—not from difficulty, but from restraining the mana eager to burst out. He was developing too fast. He needed to slow down.

On the thirtieth night, he sat before a small mirror. He stared at his reflection—round face, chubby cheeks, adorable black eyes.

“This person… this creature… is my current form,” he whispered. “Weak. Unfeared. Unnoticed.”

Then he let out a soft, cold laugh.

“And that is my greatest strength.”

The sky began to shift, dawn slowly creeping in. Isaac stood by the window, watching light lick the horizon.

A thin smile spread across his face.

“This world isn’t ready. But I’ll make sure it is. Bit by bit. Step by step.”

And just like that, the former Demon Overlord returned to his bed, cuddled his dog plush, and looked like a sweet child who knew nothing of the world.

No one suspected a thing.

And that was the most dangerous part.