I didnt quite understand the bottom left panel in page 14. He would only try to cope with things that happened during those seconds.
Does that mean MC was too fast or something else?
As you can see that MC ONLY MOVE after the boy nearly hit him, this is why the boy can't see it with future prediction. "During those second" maybe means the time after the boy move until only his sword hit our MC, not included the time AFTER the hit. So the boy can only see that he is striking the MC, but the MC doesn't move at all.