PARADISE

Paradise, also known as Nirvana or Heaven, is a higher dimensional plane. It's used as a medium to oversee the universes and all of creation.

Only those who have attained Nirvana end up here, where they become beings free from physical limitations and conventional life and death, able to oversee and govern all of creation. As it implies, the prerequisite is to cease existing in physical form.

Xuanzang's spirit protected and guided Jin Mori from Nirvana throughout the series.