[Radiant Skin]
Trembling Star Qi had two abilities. The first was to suppress other qis and the second was to disperse them. Both of these had exceptional defensive effects that made this qi type very powerful.
From Ryu's understanding, Trembling Star Qi was also an Ancestral Grade Qi. Though, these meant different things in the True Martial World versus Sacrum, the latter of which Ryu was obviously far more familiar with.
In Sacrum, Ancestral Grade Qi represented the absolute pinnacle of all qi as the only Origin Grade Qis were Essence and Chaos Qi, two qis that none could control on their own. Though, of course, this didn't include Ryu who had his Chaotic Silk Meridians.
In the True Martial World, though, Ancestral Grade Qi was quite good, but it wasn't nearly the pinnacle as there were still nine grades above it. As for the true Origin Qis, they were known as the Primordial Qis and Primordial Chaos Qis with Essence and Chaos Qi being off the scale entirely.