Billy knew that some skills could become stronger just by increasing energy output. Mana and stamina worked like that. However, at some point, it becomes inefficient. It took a while for Billy to notice that, but whenever he uses more than the double of the mana necessary to keep Fierce Aura active, his mana ends up being wasted. When he uses three times the output, Billy only receives 150 percent of the bonus when he should have gotten two hundred percent. When he used four times more, he would get 190 percent. Hence, improving the skill was necessary, but even after hours of mental training, he didn't find the answer… it was quite the problem.
"Well, let's clear my mind and see if mental training also improves my physical skills," Billy thought.
