'Could he control his strength?'
All this time, William only took his ability for granted. There was never any manual to tell him what he could do with his ability. Even the one in the website that was shown to him back then only showed that he could have greater strength than what normal people have.
And the increase in strength was not only in one side but in terms of his overall strength. It was something that he didn't expect either because it was quite bizarre. The video merely showed that if he had some basic martial arts skill, he would be able to do it with much more power.
Martial arts?
William did learn it since it was compulsory back then. But if he said that he had learned everything, it was also not true. There were still a lot of things that he was lacking back then.
Besides, he definitely couldn't stop bullet with martial arts alone.
'But I can test my skill first.'