Climate Crystal

{x}{1}{t}Target basic land is now under your
control where X is the number of basic lands
taken under your control this way.
If X is ever equal to six or higher, shuffle
Climate Crystal back into your library.
Once this card exits the battlefield, return all
lands to their original owner's control.
"...It proves very useful when you are underground
like we are, or in a building, and can't see the sky."
-William