Ilyanna
moral imperfection
When people say multiverse, are they not in fact saying multiple UNIVERSES
Isn't that an oxymoron?
It's quite possible that a lot of them mean multiple universes, which IN FACT would be an oxymoron, but I always understood multiverse as a combination of the words multi and verse, which derives from the Latin word vorsum, versum (a noun made from the perfect passive participle of vertere, meaning "something rotated, rolled, changed - at least so says wiki). So, instead of having one thing rotated, rolled, changed, we have many of them.
Back to your initial question, though - yes, by its very definition, universe does encompass everything, so there cannot be anything outside of it.
Not too quickly, though, I hope!!!I'm not convinced that the particular unique arrangement of matter which forms the self aware "me" that exists now will ever exist again. More likely I am just a struggling sputtering spark of awareness which will quickly burn out.