Amazon Rainforest

{t}: Add {w}{u}{b}{r}{g} to your mana pool.
{x}: Exile the top X cards of your library. For each spell with converted mana cost X or less among them, you may cast that spell without paying its mana cost. Then put all cards exiled this way that weren't cast into your graveyard.
The resources in the Amazon rainforest are immense beyond comprehension. Those who could figure out how to utilize them would have power beyond belief.