"Shadow Crown" was the ancestral home of the Zatara family. Everyone knew Zatanna's father, the Great Mage Zatara, but her mother, Sindella, was actually a Great Mage as well. Her bloodline and family tree were even more impressive; tracing them back led all the way to the era of Ancient Atlantis.
With a family fortune like that, having a castle inside a Pocket Dimension was perfectly normal, wasn't it?
Shadow Crown Manor had another function that Oblivion Bar lacked: it could be taken out of the Pocket Dimension and placed in the Main Dimension. Whenever they wanted to move, they could simply put it back into the space.
A single spell allowed it to travel through the universe. It was a very fine flying house, and it could turn invisible as well.
However, Zatanna's parents were the carefree sort. Perhaps they had simply been too busy with work. When Zatanna was young, she lived in Shadow Crown Castle, which had been invisibly stationed beside an island in Gotham. Yes, it had been neighbors with Arkham Asylum.
As a result, Zatanna spent every day watching those lunatics as a child, even imitating their behavior.
It was not until Zatara realized that his daughter seemed to be developing mental problems that they moved to San Francisco. After the couple sacrificed themselves, Shadow Crown Castle became a place of sorrow for Little Zatanna. Most of the time, she lived at the theater rather than in the castle.
They could have flown directly to San Francisco to find Shadow Crown Manor, but since there was a teleportation route here, of course they had to try it.
As the Sorcerer Supreme, Su Ming had barely experienced Voodoo teleportation before. Monark's kind did not count; The Mustache Mage was not a standard witch doctor.
But when