All we know is the 616 and the Ultimate U are colliding and Forming Battleworld
Battleworld to me is the bulding Blocks from the colliding Worlds and that somehow formes Battleworld and the Big 2 are responsible for it.
The Ivory Kings the Beyonder and Rabum Alai Doom. Why are the doing this? I think it has sometine to do with the 1984 Secret Wars
I have a Theary on What Battleworls is.I think when worlds collide they don't die the are transported to a seperite Universe and the Bulding blocks of each Universe makes Battleworld.That's why Marvel is saying ,There is no MU oney Battleworld and people like Spider-man Captain America ect are transpoted there.The Stores are about then in the new Universe