Atarka Monument

The dual-color entry in the mana-rock lineage that answers the flood problem by becoming a threat: it taps for either of its two colors early and, once the game has run long, animates into a 4/4 flier. The trade is steep on purpose. Six mana to activate is a real tax, and the Dragon lasts only until end of turn, so the creature mode is a finisher you reach for when mana has stopped being scarce, not a body you deploy and defend across turns. What the card actually buys is insurance against drawing lands that do nothing: the same rock that fixes your colors on turn three swings for four in the air ten turns later. Note the built-in cost of committing to that attack: because both the mana ability and combat need the tap, the turn you swing is a turn this produces nothing, so the animation is a full opportunity cost, not a bonus tacked onto a mana source. The clause that keeps the rate fair is that the Dragon is not permanent. Each animation exposes what is otherwise an inert artifact to creature removal it would normally dodge, and the moment the turn ends it reverts to a rock, so the swing has to justify putting a card that would survive a board wipe into the line of fire. Workmanlike rather than flashy, one node in a cycle covering all ten color pairs, built for slower decks that want their fixing to keep mattering late.