The Draconic Arcane Realm.
There were two ways to enter and leave the realm. One of those ways was naturally only possible for the owner of the Draconic Arcane Realm, Vigilante A, to access at will.
The other was by going through the Gate of Vitality that the System had crafted.
This Gate of Vitality used to be located in Spirit Valley, and had aided them in defeating the people of Azure Mountain.
Afterwards, it had appeared during the conference of The Alliance of Justice and Order as an entrance to the heaven-sent arcane realm.
Later, the gate was placed in a land that was rich in vitality so that it would be able to absorb vitality.