Amakusa has devise this technique specifically for snaring a person within a genjutsu while they are outside of visual range. He utilizes the moon as a medium as it would reflect off his Sharingan, thus imbuing it in his chakra. Being the moon is the highest point and source of light, there is no true blind spot a person can evade or avoid its rays. His chakra is then send outward in invisible waves of the moon that can place multiple people under his illusion or just a desired target, it requires more energy and focus to bypass others who are in the way of these waves. Those snared by this genjutsu are encased in the realm of Tsukuyomi and can experience either paralysis, image projections, or pain.