Mana Cache

The accumulation here is the whole idea, and the design discipline is the timing fence wrapped around it. Untapped lands at end step feed the charge counters, which means the engine rewards a turn where you held mana up rather than tapped out: the card pays you for restraint and converts it into a stored pool of colorless mana you can spend later. The catch is that you cannot dump those counters in response to anything; the activation is locked to a player's own turn and shut off once the end step begins, so this is ritual fuel for casting spells, not a flash of mana to fire off interaction on an opponent's turn. The genuinely unusual clause is the open activation: any player may pull a counter on their turn, which turns a stockpile of stored mana into a shared resource and invites the kind of brinkmanship where two players draw down a common pool. That symmetry is the friction the rate is paying for. Left unattended it ramps into big colorless spends; left in a pod where everyone can reach into it, it becomes a negotiation. It belongs to the school of slow, symmetrical Nemesis-era enchantments that ask you to manage a clock rather than cast and forget, closer in spirit to a Mana Flare that rewards patience than to a one-shot ritual.