Okay, to answer TwinDeath's answer. The technology can be hi-tech, but not quite into the science fiction sort. No airships or laser guns. Mostly it's realistic technology, but it can be merged with a supernatural twist. For example, bullets infused with holy water or silver. But I'll give people room to be creative

And to answer Mr. Hyde.
The Council can be found in the Conclave, a sort of realm between worlds. It can only be found by Council Members and Shadow Keepers. It's a sort of haven for Keepers to rest and relax, but most choose to live in the Mortal Realm. Other creatures may be brought there, but not without the help of the Council or Keepers.
Basically it's like a huge fortress, mixed with various styles of various cultures. It's structure is similar to a gothic church, yet the interior is a maze of halls and rooms that serve various purposes. One hall is the Hall of Mirrors, and one is the Hall of Crystal where the walls, the floors, and the ceiling is made of complete crystal, etc. I'll let Keepers and Council Members invent their own 'Personal rooms' for their own enjoyment.
The inside of the Conclave has rooms for training and leisure, and the Archives, which is virtually a vast library containing every text both mortal and dark worlder.
You're welcome to add things to it for the sake of fun, if you wish.
