The opening of the Broken Heavenly Immortal Realm and the other shattered immortal realms remains uncertain, even to the Ancestors.
In fact, as inheritors, as long as one controls any one of the Fortune, Longevity, or Fate Palaces, and possesses the strength to cross the Spirit Thunder Layer, they can freely enter the Broken Heavenly Immortal Realm.
The same theoretically applies to the other shattered immortal realms; even just possessing related inheritance items might make it simpler.
But according to the Ancestor, back when the Five Great True Immortal Paths were at war, the Heavenly Immortal World, the Mortal World, the God Celestial Court, and the Earth Spirit World all broke apart.
The Mortal World fragmented into the Four Regions, the Four Oceans, and many remote corners, with the Human Immortal Realm completely disappearing from the world.
The Earth Spirit World shattered, transforming into the Seventy-two Blessed Lands and scattered across heaven and earth.