Well, Sollie, what's sauce for the goose is sauce for the gander.
So the challenge goes to you, as well. Can you describe what characteristics a "multiverse" would have?
And since you're being all materialistic on us, can you describe how the multiverse came into existence in the first place?
We await your authoritative response.
A multiverse would be the base material for all of the individual universes to form in. It would have the characteristics of some simple medium that generated laws of physics based on geometry or topography or some other property. The laws of physics would vary in the universe of universe. Some, like ours would be stable. Others would disappear due to instability. Ours may be the only stable one.