City of Shadows

A storage land built on a Faustian bargain: it banks mana, but the only currency it accepts is your own creatures, removed from the game permanently to charge the battery. The math is grim by modern standards. You exile a body to add a single storage counter, and only later, on a separate tap, does that counter pay out one colorless. The conversion rate runs against you on tempo, and the creatures you feed it are gone for good (this predates the gentler "exile" templating; in its original printing the cards were removed from the game outright, with no reanimation hatch). What it represents is an early designer's experiment in mana as a stored resource rather than a per-turn faucet, the same impulse that later produced the cleaner storage-counter lands. Here the idea arrives raw, with the cost loaded onto the front of the transaction and the payoff deferred. The fantasy is a slow-building reservoir that eventually disgorges a flood of colorless mana for some single explosive turn, and the discipline that keeps it honest is the irreversible sacrifice: every counter is a creature you will never see again, so the land asks you to value future mana over present board presence. That trade rarely balanced in practice, but the design lineage it opened (mana you save up rather than spend) outlived the awkward rate that introduced it.