OK, version two of Material Demesne.
MATERIAL DEMESNE [-1]
Musts: Demesne, and either Miracles or some spellcasting ability. Your High Concept must be appropriate to this ability: generally, that means being some sort of god or comparable power, a really powerful genius loci, or a lord of a supernatural faction with a defined 'home base' (like a Lord of Outer Night).
Material Domain. You possess a domain on the mortal world, perhaps the size of a large building, city block or small park. You can combine your domain with those of other beings with this power, combining their sizes, but this is a permanent choice; you can't later exclude those beings. This domain is closely tied to your Nevernever demesne, though you can weaken the barrier between your material domain and your demesne down to as low as Average, or raise it as high as your Conviction + 2 (or Superb, whichever is higher). Weakening or strengthening the barrier can be done as an act of will, almost immediately; in combat, it is a supplemental action.
Enhanced Power. You gain a +1 bonus to both power and control of any spellcasting or Miracles while in your domain. This stacks with Refinement, focus items, and Miraculous Power.
Increased Domain Control [-1]. With this upgrade, you can entirely remove the barrier between your material domain and your Nevernever demesne. If you do this, any being can pass between the two with no more than a thought; no magic is required. You can still raise the barrier as high as your Conviction +2, even if you have previously removed it. In addition, you can rearrange the terrain in your material demesne by concentrating, but this takes significant time - perhaps ten minutes for minor changes like turning flat land into a low hill or a shallow pond, up to several hours for dramatic changes like turning sheer cliffs into flat land or vice versa. The new terrain still has to be physically possible unless you use other magic - if you create huge boulders floating in midair, they will immediately fall down.
Note: This power is usually taken in conjunction with Sponsored Magic - Place of Power for your material demesne.
OK, lowered cost, mentioned that changing the barrier is a supplemental action, and added an upgrade that lets people enter the NN domain without magic.
Not sure of the wording on the underlined bit, seems a bit awkward.
EDIT: Added High Concept requirement.
EDIT AGAIN: Added note about Sponsored Magic - Place of Power.
