The semi-plane once belonged to a legendary mage who had fallen for a long time. It was due to the unforgiving erosion of time that caused problems in the mage tower left behind by the legendary mage in the semi-plane, allowing Yunyu to take the opportunity to enter.
Moreover, he just happened to land in the mage tower. Without its master, even if the tower spirit tried its best to maintain, part of the magic array in the mage tower was completely abandoned and had lost its purpose.
Therefore, Yunyu was able to enter the mage tower and explore the areas unprotected by the magic array. In his naive states, Yunyu somehow stumbled into the bloodline laboratory of the long-fallen legendary mage.
There, he saw many bloodline potions that had been completed. Unfortunately, even with well-preserved measures, the essence of most of the potions had still been lost over the long period of time, turning into a pile of waste liquid.