Waterbend is a cost from Avatar: The Last Airbender that includes an amount of mana. While paying a waterbend cost, you can tap artifacts and creatures you control, with each tapped permanent paying for one generic mana of that cost.
Clues and other artifacts can become temporary mana sources without being sacrificed, while creatures that benefit from tapping gain additional utility. The mechanic appears in several different kinds of costs rather than representing one fixed effect.
