Spend only mana produced by creatures to cast this spell.

Whenever this creature attacks and isn't blocked, you may put the top creature card of defending player's graveyard onto the battlefield under your control. If you do, this creature assigns no combat damage this turn.

({T}: Add {B}.)

{T}: Add {U}.

Counter target spell.

As long as this artifact is untapped, players can't untap more than one land during their untap steps.