Difficult
This was the disadvantage of being the creator of a grade-ten technique. The very next person that mastered the technique would most likely need to be trained by the creator.
"So it is extremely difficult to master, hm…" She considered his words. She didn't seem very surprised to Rui, which was understandable, it was very rarely the case that a technique's power was not proportional to its difficulty.
"I want to see demonstrations of the technique. As well as the relevant information of Martial Artists who have mastered this technique as agreed," She demanded.