With some free time between inventory uses, Alm and Bruno turned back to studying what they had gained from the system after the tree devoured those five immortals.
This time, they didn't receive points as a reward, but two prizes. The first was: Celestial Knowledge at the immortal level about the five natural elements.
They already had knowledge of the immortal Yin and Yang and had fully studied it before. The five natural elements were a mix of Yin and Yang. It was different from the pure matrix, so it was considered separate knowledge. However, since they had already absorbed the knowledge of Yin and Yang, studying the elements would be quicker and easier.
This wasn't the pure knowledge of the laws, like the Immortal Earth Laws, but rather an understanding of nature, the interaction of the elements, and Yin and Yang within them.