C198 Yi Sheng's Successor

Other than Old Venom Man and Yuv Guzi, did anyone else on this map know? Did Yuv Guzi mention this to his master, Du Ju? If so, how could Bo Langzi not know about it? Why had he never heard Bo Langzi talk about it?

He carefully looked at the map again, then carefully put it away and closed it in the book. Then he walked back into the cave and put the book back into the corner of the iron box