This was not Lu Ye being blindly confident, thinking he could kill enemies several tiers above himself. Since leaving Green Cloud Mountain, he had slain many cultivators with higher cultivation than his own. During the Dragon Spring Gathering alone, five or six Tier Five cultivators had died beneath his blade.
The two Spiritual Patterns, Guard and Sharpness, could greatly enhance both his offense and defense, smoothing over the gap in cultivation between himself and his enemies.
So, killing an enemy one tier above him was not much of a problem for Lu Ye.
Though he had no idea what Dong Shuye had gone through, this exchange revealed something interesting to Lu Ye: Dong Shuye only had Tier Six cultivation!
Compared to the time he had pursued Lu Ye two months ago, his strength had clearly fallen somewhat. If Lu Ye had faced the Dong Shuye from two months earlier during the day, then even with his own growth, he would certainly have been no match.
A cultivator's cultivation could not possibly fall for no reason. Lu Ye secretly guessed that perhaps one of this man's Spiritual Apertures had been shattered.
The divisions of cultivation among Spirit Stream Realm cultivators were simple and clear. However many Minor Heavenly Circulation systems one had within one's body determined one's tier. But if a Spiritual Aperture was shattered, then one of those Minor Heavenly Circulation systems would naturally struggle to take shape. Spiritual Apertures that failed to form a system did not enhance a cultivator much, at most increasing their reserves of Spiritual Power.
Had the Mystic Gate done it?
Lu Ye had no way to investigate what Dong Shuye had experienced recently, but the destruction of his Spiritual Aperture was certainly related to the Mystic Gate's assault on the Nine Stars Sect camp.