The pure essence of heaven and earth contained within the Essence Stone can be directly absorbed by those at the Spirit Martial realm, enhancing their cultivation efficiency. It is extremely precious.,"There must be some secret behind this door. Perhaps the ancient hall's owner left clues within,可惜 I simply cannot open it.",Lin Feng subtly shook his head. Old Northern didn't mention this huge door to him, and it was clear that Old Northern as well as the predecessors from Cloud Sea Sect never opened this door before.。