Blue spells you cast cost less to cast
If Secret Invasion leaves the battlefield before its triggered ability resolves, the target creature won't be exiled and the enchanted creature won't become a copy of the target creature
You have a +1 that protects you from a threat, and a -2 that draws you a card and mills
Eldritch Immunity If by any chance a player is looking to end the game, has a solid board state, but is waiting for their turn, they'll need some sort of protection spell
Its interesting to note that Tarkir: Dragonstorm Commander (TDC) doesnt have any omen cards, and while Alchemy added a few cards it's unclear how WotC will use omens going forward
While Dread Return looks like a four-mana reanimation spell, the card's real power is its flashback ability, which allows you to cast it from your graveyard for free by sacrificing three creatures