Deng Yin was sitting upright on the Vajra Spirit Stone, attempting to suppress and refine his Heart Demon.
The Heart Demon, a type of Inner Demon, originates from within; Outer Demons are easy to subdue, but the Heart Demon is difficult to refine.
This is because the Heart Demon is essentially a part of one's own emotions; defeating others is easy, but defeating oneself is too difficult.
People usually don't realize their own mistakes. If everything goes smoothly, they naturally think of themselves as great and powerful. Even when faced with setbacks, they spare no effort in finding excuses for themselves, blaming others, believing they can do no wrong, and even if they make small mistakes, they see them as minor errors, while major mistakes are attributed to others, to the country, to the broader social environment.
