Meriantaa, Sea Dominus

Whenever a land enters the battlefield under your control, untap Meriantaa, Sea Dominus.
{u}, {t}: Scry 2.
{u}{r}{g}: Reveal the top card of your library. If it's a land card, put it onto the battlefield tapped. If it's a nonland card and you control eight or more lands, you may cast it without paying its mana cost. If you don't, put it on the bottom of your library.