Zones are always locked in time and space. But Zones like the black castle, in which the original owners had already made provisions, were even different.
The spirit in such Zones where the original owners gave power to oversee it had absolute power within it. They drew power directly from the influx of mana, the time-space that made a zone a thing.
To remove the hold of the spirit and tamper with its power, all you needed to do was split apart time and space and create an outside interference. And the easiest way to do that was to open a portal directly to the outside.
Now, the amount of power needed to open a portal like that from inside an unclaimed zone was astonishing. In an Iron zone, you needed to be at least Gold. Or use a gold artifact.
