In fact the speculative multi-verse is essential precisely because it affords some possibility for 'eternity' in the face of the wide acceptance of the Big Bang. As for contingency and creation ex nihilo, I'll be more than happy to discuss Aristotle contra Plato if you'd like, but to claim that eternity is self evident is self-serving nonsense.
Actually, the multi-verse theory isn't really even necessary to his proposition. All the evidence in THIS universe suggests that energy has always existed, and will always exist. There is no time or place or condition within this entire universe, where energy ceased to exist or came into existence, and in fact the universe itself would cease to exist were it not for this energy. And even though the current structure of the universe may not have always been as it is now, we have absolutely no evidence at all, in the entire universe, to suggest that this energy didn't always exist, and will not always exist in the future.
Now on the other side of the coin, we have the flimsy and rather arcane argument that because it appears to us that everything in the universe has a cause, that the universe itself must also have one, and by extension, somehow, this assumption includes the very energy of existence, itself. Yet this proposition fails in a couple of ways. One is that the appearance of 'cause and effect' could simply be a kind of illusion created in our own human minds by our recognizing existence as both a single inter-related event, and as a collection of separate individual phenomena, at the same time. The human brain is peculiar in that it functions by comparing and contrasting different views of the same phenomena, and it's likely that our recognition of "cause and effect" is a perceptual by-product of this inherent duality happening within our minds.
And secondly, the "law of cause and effect", even if it were a universal law, would END at the edges of the universe itself. And it therefor would NOT extend to whatever, if anything, happened before or after. And therefor cannot reasonably be used to support propositions involving conditions or circumstances before, after, and beyond the universe.
So as odd as it might seem to you, the proposition that the energy of existence is perpetual is actually self-evident, while the proposition that it must have a first cause tends to fall apart when applied to conditions and circumstances of the scale of the universe, and to the whole of existence.