Seducing Siren

Flying, first strike
Whenever you cast a spell, add a seduction
counter on Seducing Siren. Whenever you cast
a creature spell with flying, add two seduction
counters on Seducing Siren.
Seduce — {t}, remove X seduction counters from
Seducing Siren, where X is the mana cost of
target creature (Take control of target creature,
untap it, it gains haste until end of turn)