More than eighteen months had passed ever since Rui embarked on the field of domains. He had finally completed all four of the projects that he had conceived.

When creating new techniques, it wasn't just a matter of completing those techniques, it was also a matter of mastering them, and then also learning how to apply them in combat.

Altogether, it had been closer to two years after he was finally satisfied.

The three adaptive evolution domains and the Angel of Laplace that was an upgrade to the pattern recognition system. While he could go to work harder for years more to gain passive mastery, he had decided against that.

'I'm already experiencing diminishing returns on my training,' Rui heaved a sigh, shaking his head.

The longer one trained in a field, the more effort one needed to put into making the same progress further down the path. The path grew steeper and steeper the higher one went. If Rui were a domain specialist, he would continue pushing through.

He most certainly wasn't a domain specialist. He was an all-rounder.

He was satisfied with what he had gotten from domains, for now.

He did hope to gain passive mastery over heaven and earth bending, but that was for the future.

He also hoped to gain absolute mastery of the Angel of Laplace, but that, too was a feat he was not achieving any time soon.

Regardless, he had successfully added a new dimension to his Martial Art. The VOID algorithm, the Metabody System, the Hypnomatrix, and now domains.

"I should come up with a name for the group of domain techniques as well," Rui murmured as his eyes swam around in thought.

"Domain System…? Domain Matrix?" His mouth curled with dissatisfaction. "No."

His eyes lit up a second later. "How about the Yggdrasil System?"

The logic for the name was a tad contrived, but domains could be likened to mini-worlds with their special properties and purposes. A cool name for a group of them could be Yggdrasil, the tree of life in Norse mythology that encompassed the nine realms. (C) content.

"Ok, done," Rui nodded, adding the Yggdrasil System to the visual representation of his Martial Art in his head.

At the center of all the water was a void, representing the VOID algorithm, surrounded by the Metabody System and the Hypnomatrix. A Yggdrasil tree was added to the mix.

"I DID IT!"

A sudden yell drew his attention.

The night sky was magnified within a domain that Rui had been sitting in, guiding the Martial Master in his mastery of the technique.

It had taken him many months to master the mathematical foundation needed to even understand basic physics and then several more months to understand high school optics. It still took him several more months to master applying magnification through his domain.

Right now, he was executing a perfect telescopic domain, just as Rui had promised to teach him.

"Congratulations," Rui smiled. He was actually surprised that the Master took this long to master it. Especially given that he was an expert specialist in the mastery domain. It appeared that he still learned things slower than Rui did.

It reminded him of what Kane had told him about his conversation with his father.

Rui was still very much in his prime. He was thirty, yet he still retained the youth of a young man in his early twenties. He would retain this prime for decades to come because his life had been prolonged by the Senior Realm at the age of twenty-three, ensuring that each biological year after lasted many more years.

That was why he could do things like rapidly master the foundations of heaven and earth in three months and then complete four domain projects over the next eighteen months.

A centuries-old Master, on the other hand, needed to spend the same time mastering a single telescopic domain technique despite his affinity for it.

It taught Rui the value of his youth and how much he ought to treasure and grind while he still had it.

"Hahaha!" He guffawed. "I can now peer into the depths of the heavens!"

"Perhaps you could start an astronomy group," Rui remarked, chuckling. "Who knows, you might be the next Galileo Galilei-"

He abruptly paused as a figure appeared out of thin air before him.

She looked to be in her sixties, wearing baggy shadowy Martial Art attire. She had an amused smile on her face as she stared at Rui.

"Master Reina…" Rui murmured, stunned.

She had truly appeared out of nowhere.

Even at that very moment, he was only able to see her, not sense her. Not even Riemannian Echo could detect her existence.

As always, her prowess as an assassin came out of nowhere.

Master Gurren's eyes widened with shock as he broke into a cold sweat. "Get away from her, arrogant brat! She's no ordinary assassin!"

His Martial Heart and Martial Mind blazed into power. The domain-like Martial Embodiment bloomed into full power as he confronted the Silent Shadow. It was an impressive sight.

Yet his face was filled with wary apprehension.

Fear, even.

He hadn't sensed her either.

In fact, even at this very moment, he was unable to sense her.

She was inside his domain, standing very much within its scope and range. Yet he was unable to detect even the faintest whiff of her existence.

Master Reina, on the other hand, did not deign to acknowledge him. She didn't feel the need to.

He was unworthy of it.

She had neither used her Martial Heart nor her Martial Mind, yet he felt deep peril from her. There were very few Martial Masters who made him feel this way even in the Kandrian Empire and the Martial Union.

An electric silence occupied the atmosphere. She squatted, staring at Rui with narrowed eyes. "Training under another Master, hm? Have you been cheating on me?"

Rui palmed his face, heaving a resigned sigh. "Your sense of humor is as strange as ever, Master Reina."