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.)Watery Grave supports blue-black decks with a land that produces either color and has both the Island and Swamp types. You may pay two life as it enters to keep it untapped; otherwise, it enters tapped. That choice lets a control or graveyard deck decide when immediate mana is worth the life investment.
Polluted Delta can find Watery Grave directly, and fetch lands such as Misty Rainforest or Marsh Flats can find it through just one of its types. This helps a multicolor mana base share targets across several fetch lands. The card remains nonbasic despite having two basic land types, so a search restricted to basic land cards cannot find it.
Blue-black decks often need to alternate between cheap setup and reactive play. Watery Grave can supply black for Entomb or Reanimate, then blue for Counterspell or a draw spell on a later turn. It produces only one mana per activation, so a double-blue spell still requires another blue source rather than treating the two printed types as two mana.
Fetch timing can save life. Finding Watery Grave tapped before your next untap gives you both colors afterward without its two-life payment, provided you do not need that mana immediately. If another effect explicitly puts the land onto the battlefield tapped, paying life does not override that instruction. Include it as a searchable, flexible source alongside enough basics and other lands to support the deck’s early colored requirements consistently.
