I've been working to gain this "gatekeeper" position for a long time, I think I just recently got the main thing in place. After interacting with ancients like Adremmelech I realized it's not necessary to have all this perfection and purity in all aspects, if you get the main structure in place it works anyway. No one is going to enter their kingdoms with any hostility, it's impossible. Parts of Adre's main cave has beetles flooding in and it's dirty, but that's part of the energy flow and doesn't change anything.

What I have so far is just a curved cave entrance, but it works because of some principled function which states that "degenerate spirits cannot make 90 degree turns" just like the Chinese architecture is based on.