In the center of the underground cavern, there was a huge array formation that continuously gathered the spiritual energy of heaven and earth from the underground cavern, then transformed it in some way.
"I see."
"Yi Han used this array formation to transform the spiritual energy of heaven and earth here into health vitality to absorb."
A glint flashed across Lu Yu's eyes. In the center of the array formation, there was a control valve. Once the controller died, the transformation process would be interrupted immediately. Otherwise, this secret under the Distant North Dojo would be exposed.
If it weren't for this coincidence where a Martial Master from their Central Dojo discovered the secret door by accident, Lu Yu wouldn't have known that the Distant North Dojo was built on top of an underground cavern.
