Mystic Qi stabilizes tends to stabilize a while after reaching a certain realm, and the Mystic Qi color never changes again unless the person advances again. Even after one advances, though one can suppress their strength, one still can't issue the Mystic color of a lower realm.
Such as, even if a Heaven Mystic expert lowers his strength in combat, he still cannot issue the Mystic color of the Earth Mystic realm or lower!
This was a simple and universally known fact!
There was only one way to change the color of one's Mystic Qi: An advance in Mystic level!
And this process was irreversible!
Going by that principle, this person had somehow managed to advance from Jade Mystic peak to Earth Mystic, and then to its mid-level mark, and then to its peak in a matter of moments.
A normal, sane man would never believe that such a thing could ever be possible!