Zelara, the Seer

Hydra and merfolk spells you cast enter the battlefield with {x} additional +1/+1 counters
on them where {x} is Zelara the Seers power.
{t} sacrifice a creature: scry {x} where {x}
is the number of +1/+1 counters on the sacrificed creature
{u}{b}{g}{t} Sacrifice a creature: draw {x} cards and
lose half {x} life rounded up where {x}
is the number of +1/+1 counters on the sacrificed creature