Hall of Oracles

Lands that hand out +1/+1 counters are old hat; the gate on the third ability is the whole design. Most counter-adders ask nothing of the rest of your deck, but this one refuses to place its counter unless you have already cast an instant or sorcery this turn, and only at sorcery speed. That single clause converts a mana source into a spells-matter payoff. It does the work a prowess trigger does, except it banks the reward onto a permanent rather than a fleeting boost to whatever swung, and it does so from the land slot, where you were never spending a card to begin with. Note the exact condition: a creature, artifact, or enchantment spell does not unlock it, only an instant or sorcery. The friction cuts the other way, too. Because the counter is locked behind deploying a spell that same turn, you cannot hold up a cantrip or removal spell for the opponent's turn and still grow a creature on your own; the ability wants a deck that leads with its spells rather than one that reacts with them. Everything above the payoff is deliberately plain: colorless off the bat, any color for an extra mana, the usual filtering tax on the second ability. That plainness is the point. The land taps like any other on turn one, then quietly becomes an engine once the deck it belongs in comes online, asking nothing of the games where the spells never show.