Alchemy?

In a spacious room, Ou Yangming gently put down the book in his hands. As he turned his wrist, he retrieved the black soil.

The black soil, Concentric Knots, and Dragon Coffin were treasures that he obtained from the Wutong Tree's secret realm. He valued them before this, but things became slightly different. In particular, after seeing how Feng Xiang and Lil' Red pay so much attention to the Dragon Coffin, there was no way he could not care about it anymore.

Therefore, during Ou Yangming's few days in the library, not only did he read about smithing art and formation maps, but he also found many ancient books with miscellaneous contents as he wanted to find the answer.

Unfortunately, perhaps he was unlucky, he did not manage to find any records about Dragon Coffins.

Nonetheless, he found some information about the black soil in his hand.