Reducing air resistance, absorbing sound, concealing one's form…
This was merely Qi's application in sprinting, yet it was already comparable to the three worthless types of low-stage source energy. The comprehensive improvement of the secret martial arts system is evident. Its upper limit is high, and so is its lower limit. If it hadn't been for the blessing of the Holy Mark amplifying the effects of their source energy, the hunters possessing source energy would have found it hard to compete with the secret martial arts. If secret martial arts practitioners could be likened to tanks capable of both offense and defense, then the hunters of the Dark Hunt Organization and the Markers of Black Rain Villa would be nothing more than glass cannons.
It's important to note that these comparisons are relative. For instance, in front of Casio, even ordinary secret martial arts practitioners would be glass cannons.
No, perhaps, the term "glass cannon" is a little exaggerated.