Return of the Youngest Son with SSS-Rank Talent-Chapter 200: Demon (Part 3)

The infernal fire continued to spread, devouring everything indiscriminately. The air was unbreathable, and the ground was an ocean of boiling magma.

The demon smiled.

"No matter how much you move,"

He said in a deep voice.

"This place is already my domain."

Kael did not respond.

In his golden vision, the path began to fragment. The prediction was becoming unstable; the cost was too high. If he continued like this, his mind would collapse before the demon fell.

So... let’s change the rules.

Kael activated another Zu.

The aura around him compressed violently.

Zu Shadow Crow Step.

His figure distorted, and in the next instant, he disappeared from the demon’s field of vision.

It wasn’t teleportation, but extreme acceleration in a broken line, as if his existence was slipping between shadows.

"Hm?"

The demon frowned just as Kael reappeared behind him, several meters above.

Without wasting any time, Kael activated a third Zu.

Boiling Blood Zu.

His heart beat once... then again, with monstrous force. Blood coursed through his body like molten metal, multiplying his physical strength for a few brief seconds at the cost of irreversible internal damage.

Kael descended like a spear.

Fuuuuu!

The demon spun around and slashed horizontally with its fiery sword, but Kael had already anticipated that move.

Serpent Skin Zu.

His body bent unnaturally in midair, dodging the blade by a hair’s breadth.

Even so, the heat stripped away some of the protection provided by Zu Gorilla Mucus.

Kael landed.

The impact cracked the ground.

Before the demon could react, Kael pressed his free hand against the ground.

Seal of Silent Burial Zu.

Dull runes emerged beneath the demon’s feet. They did not glow or emit visible power, but the demon sensed something strange: its connection to the infernal fire began to desynchronize.

"What did you do...?"

For the first time, there was a real crack in its voice.

Kael moved forward slowly, ignoring the pain that coursed through every nerve in his body. Blood dripped from the corners of his mouth, but his golden eyes remained cold.

"Nothing complicated," he said. "I just buried your Concept for ten breaths."

Ten seconds.

That was all he needed.

Kael raised his sword and activated the last Zu he had been avoiding using.

Not because it was difficult to activate.

But because it always demanded a price.

Origin of Red Mana Zu.

The black-and-white aura of the sword condensed, like a collapsing star.

Kael felt something break away from him: vitality, years of life, future potential... he didn’t know exactly what, but he knew he wouldn’t get it back.

"No!" roared the demon, trying to back away.

The Seal held him back.

Kael appeared in front of him in a flash.

A single movement.

No frills.

The sword came down.

There was no explosion.

There were no flames.

Just a clean cut that pierced through the torso, the demonic core, and the essence that sustained it.

The demon’s body froze.

Then it began to crumble into fragments of extinguished fire.

"So..." murmured the demon as its existence fell apart, "...in the end... You chose to sacrifice..."

Kael withdrew his sword.

Silence fell over the ruins.

The infernal flames died out one by one, and the magma began to solidify.

Kael took a step forward... and the golden vision faded.

The world returned to its normal state, dull and silent, as if that moment of illumination had never existed.

"Fighting using the Zu is much more effective than magic and aura."

He calmly assessed.

"However, the expenditure of mana essence is also much greater."

There was no emotion in his voice, only an objective observation. He neither celebrated victory nor lamented the expenditure.

For him, combat was an experiment, and the results had to be analyzed coldly.

He wiped the blood running down his lip with the back of his hand.

At the same time, the Zu slowly returned to his magic core, merging with it as if they had never left.

The pulse of his mana essence stabilized, but the consumption was still evident.

Although the combat had ended quickly, Kael was not satisfied.

He had won, yes, but that did not mean he had fought well.

I used them in the most basic way possible...

It was a crude, primitive use—direct activation, raw power, without refinement or synergy. Any experienced Zu Master could do that.

There was no technique, no art, no depth.

His mind began to work immediately.

He thought about combination, not accumulation. About synchronization, not excess.

Zu, magic, and aura should not function as three separate paths, but as a single interconnected system. If he could intertwine them, the resulting power would far exceed the sum of its parts.

But the price...

"If I manage to do that, the mana essence expenditure would be too great,"

He calculated.

"Unfeasible in a prolonged battle against an expert."

He wasn’t fooling himself. The immediate potential didn’t seduce him. He knew that a power that couldn’t be sustained was, at its core, a weakness in disguise.

In a real fight, against someone of equal or greater skill, running out of essence meant certain death.

Kael began mentally listing the pros and cons.

Pros: Explosive power. Ability to kill enemies above his rank. Absolute versatility.

Cons:

Extreme consumption. High risk if the combat dragged on or if the enemy survived the first exchange.

Now that he had tested the Zu in real combat, and not just in simulations or training, the conclusion was clear: the potential was infinite.

He wasn’t exaggerating.

The Zu had no fixed limit; their growth depended on the user’s understanding. Unlike everyday magic or refined aura, the Zu were not bound by rigid doctrines.

But precisely because of that...

"Their flaws are just as great."

He concluded.

An uncontrolled weapon was more dangerous to its bearer than to its enemy. Kael understood this instantly.

He didn’t get frustrated.

He didn’t get impatient.

He filed the information away.

The combat had served its purpose.

He put his thoughts aside, not because they were finished, but because he had already extracted what he needed for now. There was an order to his priorities, and reflection could wait.

With steady steps, Kael ventured deeper and deeper into the ruins.