The Heaven and Earth Phenomenon would consume a massive amount of energy and could hardly be used under normal circumstances. On the other hand, with Heaven-and-Human Oneness, it was possible for Lin Yao to affect the world, although he was as small as an ant in comparison to the universe.
Of course, the foundation of the Heaven and Earth Phenomenon was a massive amount of energy. However, this technique could not be used with energy alone. There were also other factors, such as how to use the primordial spirit and energy to construct it.
Lin Yao was glad that he was studying the Heaven and Earth Phenomenon, which involved the transformation of the primordial spirit, and not Heaven and Earth Emulation, which was related to the transformation of the body. The former was less powerful and thus less difficult to learn.
'With Heaven-and-Human Oneness, I can possibly learn this. Besides, I have the reference materials.'