In fact...
What Lu Feng had done went far beyond merely employing the Mending Array Dao to level the formation's force. Aside from consuming resources no less costly than the formation itself, the key lay in the strange carving knife in his hand.
Without borrowing the sinister properties of the Bone Blade carving knife, he could never have leveled the force so easily.
In the Array Deployment Dao, leveling a formation's force required strength far exceeding the formation's grade. To level it, one first needed the absolute power to suppress it.
For an ordinary person facing the formation before them, to level its force as Lu Feng had done would require, at the very least, Heaven Soul Realm Late Stage strength. Only by drawing upon true Creation Power to suppress the formation itself before forcibly shifting it could one have even a slight chance of succeeding.
With the sinister properties of the Bone Blade carving knife, Lu Feng had effectively skipped the suppression step altogether. He directly transferred the grand formation's force into the several pieces of Red Jade embedded in the carving knife, using this sinister Bone Blade carving knife as a medium to buffer the formation's force. Only then had he managed to level it.
As for Jiang Ruoyun's notion of using this to level the sect's grand formation and infiltrate it, that would be difficult to accomplish.
Sect-protecting formations were often of an extremely high grade and guarded by dedicated personnel. Even if one was willing to expend vast resources to level their force, it would still be difficult to guarantee that no guard would be alerted.
Lu Feng's success now was entirely due to Sky Shuttle and his group arrogantly leaving. Had those people remained nearby, then no matter how little disturbance he caused, it would