Deep Water

Color fixing that runs backward. Where almost every color-changing enchantment and land exists to let you cast off-color spells, this one converts every land you tap into a source of blue and only blue: a sink, not a smoother. The design logic serves a narrow strategic axis. You pay an activation to turn a multicolor or off-color manabase into a temporary mono-blue engine, which matters only when you have a payoff that scales with raw blue rather than total mana. That payoff was the card's reason for existing in its era, when blue had effects demanding specific colored pips in volume; absent one, paying a blue mana to make your other lands produce blue you already had is circular. The activation resets each turn, so the effect is a one-shot conversion you re-buy whenever you need the pips, not a permanent rewrite of your lands. It reads as fixing but functions as its opposite: a deliberate constriction of your mana down to a single color, useful only to a deck already committed hard enough to blue that wider access is a liability rather than an asset. The artifact and enchantment slots have produced far more flexible color-changing tools since, and they almost all open color access up rather than funneling it shut.