Senior White Two said, "Inner demons are intangible, ever-changing. Their existence approaches that of thoughts. In addition, since they can amplify the weak points within a cultivator's heart... they are especially difficult to deal with. However, what if an inner demon took shape, assuming a fixed form?"
It was difficult to deal with inner demons due to them being ever-changing and intangible. Because of that, one wouldn't be able to beat them with normal methods.
Within the inner demon tribulation, the inner demons never had a fixed form. They could be a stone, a grass, a familiar person, a stranger, an enemy, an animal, or a monster beast, or even darkness, a bright moon, or the rising sun.
