Well, according to the explanation I saw on the Eight Formations of Immortals, Gods and Ghosts. This should be the Soul Condensing Pill absorbing the energy of Zidian. That's why there is a purple lightning hanging in the sky. After the Soul Condensing Pill has absorbed all the energy from Zidian. It will disappear again. As long as the open door of Wanxian Pit is closed. If we want to find it again, it will be difficult....