Repurposed Domain

Rui began sparring with as many Martial Masters as he could. He overcame the power gaps and most Martial Masters by sealing entire parts of his Martial Art, restricting his power to whatever was necessary and forcing himself to overcome them with sheer Adaptive Evolution.

This way the difficulty allowed him to extract some meaningful experience from the battle. As long as he could restrict enough techniques from the battle, he could essentially recreate a power dynamic similar to that of fighting an equal.

If he didn't do this, the number of Martial Masters that he would be able to fight would be extremely scarce as he was a particularly powerful high-grade Martial Master with the Yin-Yang Spear at his disposal.

Of course, this came with its downsides as well.

The more he held back, the less relevant the experience of that particular battle became. After all, he wouldn't hold back so much in a real fight.