Cultivation of Immortality: I Am Looking for Immortality in My Dreams

After Mengtong learned about the world of cultivating immortals, he discovered that the essence of cultivating immortals is: the strong use the weak as a furnace, the sects in the upper world give the fragments of exercises, and the sects in the lower world are like fish ponds. If you are not cruel, you will not be able to become an immortal. From being unwilling to accept it to being forced to join, why is the cultivation of immortals like this...