Speaking of the door of the discussion hall, it had quite the origin, it was created by the founder of Northern Plains Zombie Alliance.
This predecessor's name was already lost in history, but his methods were simply divine.
The door was filled with all sorts of dao marks, some people had guessed that consumable Immortal Gu were used on it.
Only immortal zombies in Northern Plains could be acknowledged by the door, and would be able to push it open. If it was not someone who ascended to a Gu Immortal in Northern Plains, their immortal aperture world would have the heaven and earth qi of other regions. Once their hand is placed on it, they would be repelled. If one was a Northern Plains Gu Immortal, but not an immortal zombie, this door would heavier than a mountain, they would not be able to push it at all.