Nyseria, Hydra of sailors doom

Nyseria enters the battlefield with X +1/+1
counters on it
{u}{u}{u}{u}{t}: destroy target creature that was cast
with blue Mana this turn, then, put X +1/+1
counters on Nyseria where X is the amount of
blue Mana spent to cast it
Sacrifice a island: destroy target land
you go first— John Black