Dreamcaller Siren

The flash-flyer-plus-tempo package is old territory for blue, but the conditional tap is what gives this one its teeth. Played at the end of an opponent's turn with another Pirate already down, the enter-the-battlefield trigger taps up to two nonland permanents: two would-be blockers locked down, or a creature and a mana rock, or whatever stands between you and lethal next turn. That window is the whole reason to hold it: dropping it on a clear board does nothing but add a 3/3 flyer, while ambushing into a developed board can swing a race in a single attack step. The Pirate clause is the cost of the upside, tying the card's best line to a tribal commitment rather than letting it function as a generic flash threat. The blocking restriction is the quieter tax: a 3/3 with flying that can only stop other flyers means it pulls its weight on offense and leaves the ground undefended, reinforcing the aggressive, tempo-forward role the rest of the card points toward. It is built to be a clock with a built-in unstacking of the opponent's defenses, not a wall.