The young man sprinted through the forest, seemingly unconcerned about drawing attention or the potential dangers he might attract with all that commotion. In fact, his gaze hinted that "attracting trouble" was precisely his intention, given the indiscreet manner in which he raced forward.
If a cultivator with a high level of cultivation of the Flux Synchronization witnessed firsthand the velocity of this dark-clad martial uniform-wearing young man, they would likely estimate his cultivation level to be at least 45% to 50% synchronization, a rough equivalent to the Second Stage of Bone Realm.
Another point that a perceptive cultivator would notice was the way that young man moved. None of his motions appeared exaggerated; there was a deliberation and precision in what he did and how he did it, allowing him to change direction at will.