Mudouken

Mudouken (無道拳 lit. "Path of the Empty Fist") is a state of consciousness transcending ordinary perspective, born through spiritual and mental refinement. Bearing common traits with states of being within Zen, martial arts, and spiritual perfection, it is the power to act without being attached to emotions and thought, free of fear, anger, pride, and ego, to draw upon the contents of one's heart intuitively without obstacle and hesitation, and to be aware of the world and to know one's place and meaning within its vastness, to flow with all of creation without the need of worry, desire, and doubt. The Mudouken is the other half of the Yin Yang dual philosophy that is deeply ingrained in the culture of Amaterasu.

It is the complete opposite of the Satsui no Hado. As such, it can only be used by a person of pure mind, compassion, mercy and peace. Such a person must have embraced the peaceful and spiritual aspect of the art to their fullest extent. Just like the Satsui no Hado, if Satsui no Hado expresses its power by killing and destroying opponents, inflicting great agony, great suffering, and ultimately death, Mudouken is the complete opposite, the opponent will be taken down and neutralized without any damage or injury at all. What they will feel is a fist that is literally empty and devoid of any malicious intent and harm, ultimately saving the opponents from their murderous self. This is heavily tied to its root: The Satsujinken  (殺人拳, lit "Killing Fist" ) transformed to become the Katsujinken (活人拳 lit. "Saving Fist") created by Tama Tenkai as its first progenitor.

Gaoh has practiced with this power throughout his years of training with Rekka, and after he had completed his training Tama deemed Rekka and Gaoh a worthy successor of the dojo orphanage. Gaoh identifies the Empty Fist not as the power to defeat one's enemies or snuff life meaninglessly, but as a power to grow in skill and as a person, completely distinct from the Satsui no Hado.