Poseiden, God of the Sea

Indestructible, Islandwalk, Haste
When Poseidon, God of the Sea attacks, put 3 Blue 2/1 Mermen onto the battlefield tapped and attacking.
{t}{1}{u}{u}{x}: Destroy target nonblue land. Repeat this process X times.
{3}{u}: Up to 3 target creatures don't untap during owner's next untap step.