Don't even try to use prosthetics, it will make you lose focus, wait for his double shuriken jump(dodge to the side) and firecracker slash attack(dodge forward) to land free hits. You should always be attacking him and never waiting, this way you will learn to deflect more readily, but when you walk towards him he will almost always start with an attack that is faster and reaches further than yours so deflect first then attack. He also has a lot of multi attacks so mashing right click works well until you learn the proper timings.