At this moment, Lu Waner was truly terrified, knowing that the Heart Demon is invisible and colorless, and no one can detect it. Once it clings to you, it amplifies all your negative emotions, slowly leading you to degeneration until you're completely demonized, then the Heart Demon takes over your physical body.
After that, your consciousness will form a new Heart Demon, and by that time, you will basically have no consciousness at all, relying purely on instinct to slowly guide yourself to occupy the bodies of others.
Lu Waner is really afraid of degeneration, after all, she is living a very happy life right now.
