As the Nexus of all Realities, the Crystal can allow travel between universes, but opening the Crystal could cause the mass of the neutron galaxy inside to suck in the entire universe and cause a chain-reaction across the Omniverse, destroying all universes in existence. The city inside can only be reached once every million years: when specific galaxies are aligned, the M'Kraan Crystal will allow entry for a short period of time. It also houses the White Hot Room, the place in which the Phoenix Force places all beings to heal them or return them to life. As it is a singleton across all universes, the reality-hopping Exiles have recently figured out how to use the Crystal to visit selected realities; on the Age of Apocalypse, Dark Beast discovered a means to travel through the Crystal to a