A red sword releases sharp but powerful sword energy. This sword energy is specific to this sword art meaning, Zhang Chen hasn't realized his own sword energy but can produce sword energy of specific arts such as Seven Emperors Killing Sword.
Sword Energy has four attributes, and the advantage of practice your own sword energy is; you can add all four attributes to your sword energy. But it is kind of hard while practicing sword art and using sword energy related to that art is nothing hard because you are practicing something that has been already practiced.
Every martial art written by the creator is fully detailed about everything related to it. Such as his Seven Emperor Killing Sword has described a short way to access Power attributed sword energy. But if Zhang Chen tries another martial art, then this Power attributed sword energy may not be helpful to him except giving him experience.
"Splash" "Thud"
