Sorcery
G
Join Forces - Starting with you, each player may pay any amount of mana. Each player may search his or her library for up to X Basic land cards, where X is the total amount of mana paid this way, puts them onto the battlefield tapped, then shuffles his or her library.
This seems like a potent early answer to the color Brown. You pay X mana and get X-1 basic lands to show for it. They get no benefit from the card, and you've negated their spheres and permanent count advantage strategies.
It's not for every deck, but it doesn't seem awful or unplayable.
