The Omen Collection [Blu-ray] contains only four movies: The Omen (1976), Damien: Omen II (1978), Omen III: The Final Conflict (1981) and the remake of the first film: The Omen (2006). Missing from the collection is the made for TV movie Omen IV: The Awakening (1991).
This collection is incomplete and the title is misleading. My 'collection' of the Omen series contains a neat little box of four Blu-Ray disk, and beside it, a DVD case with the 'missing' film that the studio forgot to include. The Awakening isn't available in the Blu Ray format (yet?).
This isn't a collection, it is an assortment.