Orb of Eterntiy

At the beginning of your end step, if Orb of Eternity is untapped, and you control one or more untapped lands, put a charge counter on Orb of Eternity.
{t}, Remove a charge counter from Orb of Eternity: Add one mana of any color to your mana pool.
{t}, Remove three charge counters from Orb of Eternity: Draw a card.