John's words seemed to echo throughout the chamber, as it fell into a deafening silence. Swearing on the heavens, and ones on Dao Heart, was an incredibly serious thing. If one was telling the truth when they made such an oath, nothing negative would happen.
However, if one made such an oath to the heavens and themselves and were lying, a flaw in their Dao Heart would appear. The Dao Heart was the cultivators' entire being, their resolve, determination, and even involved the mysterious force of Karma.
When they lied on their Dao heart, a flaw would form. It was undetermined how big this flaw would be, or when it would appear during their cultivation journey, but a Dao Heart flaw would eventually affect their cultivation, making them unable to advance anymore. Such a thing was basically a death sentence to cultivators, who stove to raise their power above all else.