Rui nodded, absorbed. He knew that domain techniques covered a lot of areas intrinsically; it was what defined it and set it apart. This naturally meant that a lot of energy was spread out, resulting in low energy density, which could easily result in a weak technique whose effects are too spread out.

"The most common means by which this shortcoming is solved is by ensuring that, despite being spread across a large area, the entire area impacts the target of your technique in some way. If the entire area that is receiving energy from your domain technique is impacting the target directly or indirectly, then the total spread energy will end up impacting your target directly or indirectly," The Master explained. "In this case, the low energy density doesn't matter because no amount of energy is being wasted. The entire area impacting the target means the entire energy you are outputting is hitting the target. Suppose only a portion of the environment is impacting the target. In that case, the energy in the rest of the environment will not impact your target, and thus will be underutilized and wasted."

That made sense to Rui. This way, the domain's shortcoming was mitigated while its advantage of highly successful hit rates was retained.

"That is the most common consideration regarding the field of domains," Master Gurren remarked. "However, it is not the only one. Domains may seem simple conceptually, but in my many years of exploring, I have come across immense depth in them that they are never given credit for. That is what I will convey to you, arrogant brat."

Rui nodded, smirking. This was why he had come to Master Gurren instead of just searching for random domain techniques in the Martial Union's library.

Centuries of experience resulted in wisdom and understanding that no scroll or book could compete with.

"The field of domains can be divided and organized in many ways," The Master explained. "One important distinction within domain techniques is the nature of its energy requirements. Does a domain technique require a constant supply of energy to maintain it? Or does the technique require some amount of energy to set it up and then no longer require any energy for maintenance? The latter usually involves shaping the environment or changing its state in some way. The former is usually a domain of a temporary effect that is generated by the user constantly exerting and manipulating force onto the environment. It tends to be stronger and more energy-consuming while the former tends to be weaker and less energy-consuming."

"In addition," The Master rapidly continued. "Domain techniques can also be divided by their target scope, which is not the same thing as the domain area itself. Some domains cover a wide area and many objects but have a limited target scope. These techniques often leverage a large amount of area to work against or for a single target, just like I discussed earlier. However, there are some domain techniques that are designed to target every single thing in their vicinity. These are meant for when faced with a large number of opponents and targets, generally."

"I see," Rui murmured. "That is…interesting."

He may choose to create a technique like that, though he wasn't sure about how necessary that measure was. If he faced a swarm of equals, then he was probably screwed, but if he was swarmed by weaklings, then he wouldn't need a domain in the first place.

"That gives you a general and broad overview of domain techniques and how they're categorized," Master Gurren remarked. "There are very defined and inescapable shortcomings of domain techniques like their high energy consumption, but there also are very concrete hit rates. As long as you can create potent effects in the domain, the negatives of domain techniques are compensated for, and you're left with the overwhelming benefits."

"However, the one disadvantage that really holds back the field of domains from becoming mainstream is the difficulty of individualizing them," Master Gurren explained. "Manipulating a large portion of the environment is difficult, and it's even more difficult to make individualistic progress in this field. Because there are a limited number of principles through which one can manipulate such large swathes of the environment."

Rui nodded. "I'm not too worried about that."

Rui was certain that he could bypass that limitation with new principles of Physics that he was aware of; he already had a lot of good ideas on how to go about it. He would immediately begin testing them out when he had the foundations of domain techniques down. Copyright by Nôv/elDrama.Org.

"Hmph, as expected of an arrogant brat," Master Gurren huffed. "Do you think you can chart new territory in domain techniques?"

"Absolutely, I'm going to create domain techniques that adapt the domain to counter my opponent," Rui replied. "That will most likely require some effort, but I am confident that I can achieve it."

"Adapt the environment to your opponent, hm?" The Master raised an eyebrow. "Domain techniques are already suitable counter against maneuvering and speed-oriented Martial Art. This is because they invalidate the biggest benefit of maneuvering or speed: evasion. Evading a domain is a task that nobody should find themselves doing. If you do, you ought to question everything that leads to those sets of events."

Rui chuckled. "I would only need to if I come across an extremely lethal domain. Are there any domains that instantly kill their opponents without any opportunity for resistance?"

"Indeed, arrogant brat" Master Gurren nodded. "These domains are based on powerful principles and are excessively difficult. It's not that just about everyone can master them. The few grade-ten domain techniques are nothing short of magical."

Rui smiled, growing excited by the prospect of creating such techniques. Just the idea of manipulating the world around him in extraordinary manners to create extraordinary domains that adapt to the environment to counter his opponent was fascinating to Rui. He couldn't wait to take this next step and expand the scope of his Martial Art.