human literally cannot block laser, augmented or not. it's laser, a light, does nobody ever know the speed of light is??
but if you say, watching the gun and predict it's trajectory then it's possible
The first chapters already had the dude dodge directed-energy weapons with his spaceship, so deflecting lasers with a sword isn't anything more fancy. This is just that kind of story. Star Wars at least explained it with the supernatural abilities granted by the Force.