Secluded Steppe

Flood insurance built into the manabase. The trade is explicit and self-correcting: keep this in the early game when you want a white source, and it taps like any other land, the entering-tapped clause being the tax you pay for the option. Draw it in the late game when you already have all the lands you need, and you spend a single white to discard it and dig one deeper, converting a dead topdeck into a live draw. That second mode is what made the cycling lands a fixture of grindy control shells: they let a deck run a slightly higher land count without paying the variance penalty, because the surplus lands stop being surplus. The cycle that introduced them, one per color, addressed a tension as old as deckbuilding itself, the pull between flooding and screwing, and resolved it with a mechanic rather than a flashy effect. The white member belongs in decks that want to play long games, where every card spent on mana is a card not spent winning, and a land that can become a card late is worth the tapped-land cost early. The elegance is that nothing about the design is wasted: in a flood, it is a cantrip; in a screw, it is a land; and the only price is one turn of tempo paid up front.