The Netherworld Realm is like another universe that exists in a different dimension but runs parallel to the material world.
It is infinitely vast and connects to every world; each sector has an administrator who manages the samsara cycle for the material world under its jurisdiction.
King Yama was the administrator of the Earth sector—that was until the Dark Emperor killed him.
Nevertheless, the Netherworld Realm wasn't as simple as a world for the afterlife of the deceased. It was far from it.
It is a spiritual world for all spirits, whether they were born in the Netherworld Realm or descended from the world of the living.
The underworld was just one side of the Netherworld Realm.
Rumble…!
Albion's grumbling stomach made him look for quick shortcuts out of the Region of Desolate Famine as he glanced up at the sky and the ground below.