Iado Research

 Iado, the way of the sword, is a martial arts developed as a defensive method to counter surprise attacks and enemy raids in the fifth-teen and sixteenth century. The point of this martial arts is to slay your opponent with one stroke of the sword after unsheathing it. Furthermore Iado consists of working in one smooth motion based of your opponents moves consisting of set base of movements called Kata. This martial arts was created by Hayashizaki Jinsuke and he designed for castle guards to parry their opponents move and strike back in one movement. My question would be how many years did it take you to master this type of technique that is known for its difficulty?