The usual fallacy is that, in every universe, many futures splay outward from any given moment. But in some universes, determinism runs backwards: given a universe’s state s at some time t, there are multiple previous states that may have resulted in s. In some universes, all possible pasts funnel toward a single fixed ending, Ω. If you are of millenarian bent, you might call Ω Armageddon. If you are of grammatical bent, you might call it punctuation on a cosmological scale. If you are a philosopher in such a universe, you might call Ω inevitable.