Hengen Muso

Hengen Musou (Peerless Transformation|Unparalleled Transformation) is a a legendary fighting style that was born out of the desire to save the world without having to rely on Heroes. It is said to have never lost on the battlefield. The last practitioner, Granny, said that the style was no longer needed in this world and planned to take it with them to the grave. But after being helped by Naofumi, she decided to pass on the legend for the sake of the world. There is no specific weapon with Hengen Musou Style meaning that a medium is unnecessary but at the same time anything can be used as a medium.

History
The developer of Hengen Musou style and founder of the Hengen Musou School was an adventurer that wanted to overcome danger without relying on the heroes. The style was extremely powerful and established itself in the histories of countries around the world. However, half a century prior to the current hero summoning internal discord caused the death of a majority of its practitioners. Those left all swore to never pass it on. Granny, the last practitioner, decided to teach the style to Naofumi's subordinates after being helped for the sake of the world.

Chi
Chi is the basis for Hengen Musou. Like magic, every person has Chi in their bodies. Some, however, have more talent than others in manipulating it like Rishia and Atlas. Rishia is special in that she can learn almost if not all of it and is considered to be a talent is only found once every 100 years. Atlas has innate talent and perceives the world around her through sensing Chi. The Four Legendary Heroes all have irregular Chi flows which disallow them from using Hengen Musou. However, they can counter Hengen Musou if they train their Chi properly.

Peerless Activity
Peerless Activity is the time period in which Chi is actively being used. Eclair is only able to use it in bursts while attacking or avoiding while Rishia excels at maintaining peerless activity for a extended periods on something like a low output but she can also use it in bursts. In essence it's like an ‘Overdrive’ skill or attack in games giving the user an ability boost for a certain time.

Other
Eclair mastered the Peerless Transformation Sword Style. She finished self-training through beating Ren repeatedly. c219