Land
T: add U to your mana pool
Tap an untapped permanent you control, T: add WW to your mana pool

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GW
Enchantment
Whenever one or more Elfs are put into a graveyard from the battlefield, target player may pay G. If that player doesn't, add one mana of any colour to your mana pool
Discard a card: up to five target permanents you control can't be the target of spells and activated abilities until end of turn

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WUBRG
Artifact Creature - Spirit (1/1)
When ~this~ enters the battlefield, destroy all creatures. They can't be regenerated.
~this~ can't block

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AlexChurchill/MagicCardGenerator