One Sword Breaks Mountains and Rivers is the common name for this move, but in truth, it has another name—Mountain and River Secret!
Or, to be exact, Mountain and River Sword Secret!
To gather the might of heaven and earth, and unleash such force that it alters the universe, that is known as a Secret!
Within the Great Jin Dynasty, any martial arts skill referred to as a Secret is of Third Grade or higher, and such techniques are often the foundational treasures of major powers.
Moreover, it's not simply a matter of having such a technique; to master these preeminent martial arts skills, one needs talent and insight!
Thus, in the world, there are many supreme martial arts skills that have no successors and have consequently lost their lineage.
For instance, the Mountain and River Sword Secret that Yuwen Zongheng is currently demonstrating has not been mastered by anyone at Dong Song Academy for nearly a hundred years.