The construction of the Heart Domain is actually quite simple.
Similar to building a house.
First, find a suitable open space. After finding the space, lay the foundation. Only after laying the foundation would one consider constructing the framework of the house, setting up the pillars, the roof tiles, and so forth.
In short, there is a sequence to follow.
The construction of the Heart Domain follows this same principle.
First and foremost, it is finding the door to the Spirit Realm.
This, Brian had somehow completed unwittingly.
His door was located at the center of his forehead.
The door is the coordinate that connects the Material Realm and the Fourth Dimension (Spirit Realm).
Having the coordinate is like having a foundation.
Then, using spiritual power, simply sketch out an isolated bubble, a space isolated from the fourth dimension.
This bubble is the Heart Domain.
There are two types of Heart Domains in size.
One is a personal Heart Domain.