The Martial Unity

The Martial Master stopped at an incredible altitude in the sky. He glanced back, snorting at Rui who had been left behind. He himself would have loved to go further, but Martial Masters too were limited by the necessity to breathe air. He couldn't any further.

The night sky glowed with an endless ocean of stars twinkling in the sky.

He fixated on them intently as his powerful vision was able to peer into them far deeper than any human possibly could.

The cognition that his Martial Mind gave him allowed him to gain an intuitive understanding of them. While he did not possess a theoretical framework for the magnificent shining existences that were embedded deep in the sky.

Interestingly enough, he never once paid any attention to the moon. In fact, his mouth curled in contempt every time he looked at the gibbous moon. He only was interested in the natural state of the universe.

He was not interested in a man-made object.

He continued spectating the night sky until dawn arrived, before finally declining from the sky, and returning to his hut.

The arrogant brat was waiting for him there.

"I thought I told you to get out of here," Master Gurren growled.

"If I didn't have anything to do," Rui replied. "But I do."

"I told you, I don't teach," Master Gurren snorted.

"But you do stargaze," Rui remarked turning to the dawning sky. "Unexpected, for a Martial Master. Is that why you became a Martial Artist?"

Rui couldn't help but suspect that.

"You're awfully nosy for a brat that has no business being here," He narrowed his eyes. "Perhaps I should kill you right here and now. Nobody would ever know as long as I hide your body well."

"You're too kind to do that," Rui replied matter-of-factly.

"Am I now?"

"You ensured that your Martial Embodiment would not hurt any animal or human in this mountain range even when you didn't have to," Rui replied. "That shows you care."

"Hmph, don't push me, brat, everybody has limits," The Martial Master snorted. "You really are arrogant. Give me one reason I shouldn't kick you out of here."

Rui smiled. "I can give you a Martial Art technique that will allow you to observe stars better. Far better than any existing telescope, I promise."

The Martial Master narrowed his eyes. "There exists no such Martial Art technique."

"Not physically, no," Rui replied. "But it exists in my mind. I created it after I realized you could use it."

Optics was something one studied in high school and even more in-depth in college for a bachelor's and later master's degree in Physics. Once realized that his knowledge could work as a fine bargaining chip for the Martial Artist.

"Inside your mind?" The Martial Master narrowed his eyes. "Do you expect me to believe that nonsense? There's a limit to arrogance."

Rui smiled wryly.

The formula magnification was rather simple. Rui knew that he probably could create a telescope technique that used that atmosphere as a lens.

Any and all transparent media that allowed for light to pass through them could serve as a lens. Of course, it was complicated, he would need to manipulate the air to alter what was known as optical density, which was a measure of how much slower light was in a medium compared to a vacuum, and then create curvilinear lenses out of the air to magnify light as much as possible.

"If I improve your stargazing experience by ten times, are you willing to help me out?" Rui asked him.

The Martial Master didn't respond, simply staring at Rui intently.

"I'll take that as a yes," Rui smiled wryly. The Martial Master was too aloof to even verbally concede.

Rui turned to the side, activating a crude breathing technique that he had created while the Martial Master stargazed all night.

He brought his hands in front of him breathing in a particular way, it created a small pocket of air that was much more dense than normal.

Master Gurren's eyes widened as the image that the light passing through the pocket air was a zoomed-in version of a distant mountain.

"That's all I was able to do overnight," Rui replied, heaving a sigh. "It doesn't rely on any energy-consuming esoteric substance that normal telescopes rely on. I presume that that is why you don't use them. However, to create a technique fit to gaze at stars, I will need to master the foundations of domain techniques."

Master Gurren narrowed his eyes as he understood the proposition that Rui was making. He had created a circumstance that not only was he offering something that Master Gurren wanted in return for a powerful foundation in domain techniques, but he had also made what he wanted necessary to fulfill what Master Gurren wanted from him.

"Who are you?" Master Gurren asked Rui with grudging curiosity.

"Just an arrogant brat, Your Mastery," Rui bowed lightly, smirking.

"Hmph, you refuse to tell me your name? Arrogant brat."

"So what do you say?" Rui asked. "We can help each other out."

Master Gurren snorted. "Hmph, you truly are arrogant…Show me that technique again."

Rui tilted his head with a smirk, raising an eyebrow.

"Alright, fine. I accept your deal." The Master begrudgingly conceded. "Now show me that technique."

"Of course," Rui replied, smiling, before demonstrating the prototypical technique.

He wasn't worried that he would be losing out on the deal by displaying the technique. He wouldn't be able to make anything meaningful from it, the physics and math behind was complex. Rui just made it look easy.

He had been doing this for a long time, after all. He had grown to become something of an expert in converting Physics to a Martial Art technique after doing it so often. Considering he had succeeded with difficult techniques like the Riemannian Echo and the Pathfinder technique, he had no doubt in his mind he could succeed with the magnification formula for a convex lens.