The reason why Immortal Kings could become overlords was that they were not afraid of the destruction of their physical bodies. As long as his true soul power was still present, he could be considered an undying existence.
The most important thing to break through to the Immortal King Realm was true soul power, followed by the Immortal Essence Sage Body, also known as the Dao Embryo.
Dao runes circulated within, that was why they could communicate with the Great Dao of Heaven and Earth. As long as one was an immortal king, they would definitely be able to sense the great dao of heaven and earth. The difference was that some were clear, while others were blurry.
