Legendary Artifact
Sacrifice ~this~: put a 1/1 Myr artifact creature token onto the battlefield
Sacrifice three Myr: put a charge counter on target Swamp
Threshold - If you have seven or more cards in your graveyard, spells cost all players an additional ''Tap an untapped white permanent you control'' to cast
Converted mana cost: 4
AlexChurchill/TypeFourArtifactGenerator