It manipulates atoms of everything within Ichiryuu's immediate vicinity automatically causing them to act in such a way that it reverses all the positive functions of the body as well as inanimate matter. For instance it stopped the lungs from receiving oxygen, the heart to stop pumping blood and almost shut down Midora's brain who only escaped because he knew the mechanics of Ichiryuu's technique and actually possessed an even more hax ability. It also can make slow things fast, rock become soft, and even mess up a person's perception so badly that they can't hit him when he's standing still. That was a rough explanation. It can actually go beyond that.