720.2 The text that appears in the inset frame on the left defines alternative characteristics that the object may have while it’s a spell. The card’s normal characteristics appear as usual, although with a smaller text box on the right.
720.2a If an effect refers to a card, spell, or permanent that “has an Omen,” it refers to an object that has the alternative characteristics of an Omen spell, even if the object currently doesn’t use them.
720.2c Although omen cards are printed with multiple sets of characteristics, each omen card is only one card. For example, a player who has drawn or discarded an omen card has drawn or discarded one card, not two.
720.3c If an Omen spell is copied, the copy is also an Omen. It has the alternative characteristics of the spell and not the normal characteristics of the card that represents the Omen spell. Any rule or effect that refers to a spell cast as an Omen refers to the copy as well.