Asher's hand was a blur as he kept attacking endlessly, although Williams met all the attacks, he could tell the boy was getting tired due to the heaviness and weight that came with each strike. He could also see that Williams' proficiency was rising in real time; after a point, he stopped sliding backwards entirely and held his ground with growing stability.
It wasn't that Williams had suddenly perfected the blocking technique, Asher knew that after this moment, if Williams doesn't continue this particular training to perfect it and make it second nature, then he would simply revert back to square one again, but Asher made no mention of it, that part was left entirely up to Williams and Williams alone, it had nothing to do with him.
