there exists an infinite number of worlds, so it 
can be said that everything and anything must and will exist as well.  

Um, thats a common (and annoying misconception) just because somethings
infinite doesn't mean it contains everything. eg. There are infinite
numbers, each one unique, but that still doesn't mean you can count to
orange. Similarly, you can generate infinite worlds identical to each
other apart from a single number on a wall somewhere.
Even if, as is theorised, the universe splits everytime a quantum decision
is made, there will still be a more likely result when all possible results
are combined (though it gets kind of dodgy here trying to say that this
infinite group of worlds is larger than that infinite groups of world)

I'm sorry to jump down your throat about this but I'm sick of people
trying to convince me that since the universe/multiverse is infinite then
everyhing imaginable exists somewhere, including fictional universes.