The Biblioplex

Zero or seven: those two numbers are the entire mechanism, and they are not arbitrary. Empty hand is the domain of the deck that vomits its cards onto the board early; seven is the ceiling most decks brush only after a full refill. This taps for colorless like any painless utility land, but the second ability, which layers two mana on top of the tap, refuses to fire anywhere in the crowded middle where most hands actually sit. That gate rewards the swing between extremes instead of the steady grip, a deliberate way to keep a repeatable selection engine off the tables that would otherwise abuse it. When the condition is met, the payoff is narrow and exact: peek at the top card, take it if it is an instant or sorcery, and if you pass on it (or it isn't a spell you want) bin it to dig one deeper next time rather than leave a dead draw stranded up top. Cut the "zero or seven" clause and you are left with an automatic-include filtering land that produces colorless mana on the side; keep it, and the card demands you architect your hand toward one of two poles before it earns its slot. The hand-size restriction shoulders every ounce of the balancing a colorless-only mana source could never manage on its own.