This technique, 'Absorbing All Rivers', relies on absorbing the energy from deceased cultivators in order to enhance one's own power.
To put it bluntly, this 'Absorbing All Rivers' belongs to the dark arts, which surely makes it despised by those on the Righteous Path. In fact, such methods don't even exist in the current Demonic Path. If Ye Chenfeng were to perform it publicly, he would likely become everyone's enemy immediately.
After all, this 'Absorbing All Rivers' is considered defying the heavens, coveted by both the Righteous and Demonic paths. The Righteous Path folks would seek to apprehend Ye Chenfeng in the name of eradicating evil.
