Furycalm Snarl

The reveal clause is a bet on your own opening. Where a check land wants a typed land already on the battlefield and a pain land charges you life for the privilege of untapped color, this one asks only that you hold a Mountain or Plains card in hand and flash it. That swaps the pain lands' life cost for an information-and-inventory cost, and the swap is the whole personality of the two-color reveal cycle: the enabler is a card in your grip rather than a life total you are willing to spend. The reward front-loads, because the qualifier gets scarcer as the game runs. Early, with a full grip, this is a painless untapped dual. Later, once the right cards have been spent or drawn out, the reveal grows brittle, the land comes down tapped, and that tempo hit stings most in exactly the turns you can least afford it. Note that the requirement is a card sharing the type, not a literal basic, so shocklands and other typed nonbasics satisfy it too, which quietly widens the enabler pool beyond what the text seems to demand. And note what it does not check: the board is irrelevant. A developed battlefield buys you nothing here. What matters is the hand, and a hand that lacks the right card, however far ahead you are on the ground, still drops this tapped. The design punishes the hand without a Mountain or Plains specifically, and only that.