So in the Marvel Universe we have the M'Kraan Crystal which is supposedly the nexus of all realities and contains a city, a gem containg a neutron star, and the white hot room - all of which are separate places, though it has been said that the white hot room is somewhere in the city and the gem containing the star is in the centre of the city. We also have the Panoptichron, which is a crstal palace thing that can send people to any reality but appears to exist outside of space and time. But we also have the tower formerly occupied by Excalibur which serves as a bridging point between every other universe (so essentially a focal point for all realities). So what is the deal with Otherworld and the Exiles really? How was Roma not aware of a bunch of people popping in and out of a bunch of realities that are supposedly monitored by her from the starlight citadel? Where does the M'Kraan crystal fit into all this? And wasnt there a nexus of reality of something associated with Man-Thing? Alan Moore's genius creation of numerical worlds really helped to pin down the whole omniverse thing - but nowadays with about a million ways of crossing time/space/ reality, and the blurriness of what is a dimension and what is an alternate Earth really muddies up things I find.