Altar to Demeter

{3}, {t}, Put an offering counter on Altar: Search
your library for a basic land card and put it into
your hand.
{4}, {t}, Remove an offering counter from Altar:
Put a land card from your hand onto the battlefield tapped.
{6}, {t}, Remove four offering counters from Altar: Sacrifice any number of lands, search your library
for that many land cards and put them onto the battlefield tapped, then shuffle your library.