The Kun Realm was the sole entity in control of the Rune Realm, a realm whose power allowed it to condense portals to anywhere in the Greater Universe.
It wasn't actually possible to arrive anywhere they pleased. It actually functioned by drawing information from the Mong Realm. After all, it had once been an important location of the Mong Realm.
So, anywhere that the Gods of the Mong Realm had been was recorded in the Mong Realm itself. With that being said, this information also existed in the part of the realm that had branched out to become the Rune Realm.
As there were countless locations installed in it, to a certain extent, it could be considered as the Rune Realm being able to condense portals to anywhere in the Greater Universe.
And a few of these portals led into the Bolg Realm. Of course, the Mong Realm had infiltrated it in the past to scout for information, treating it as a potential target to invade in the future.
