Omen Machine
New Phyrexia — rare
Artifact
Omen Machine rulings:
2011-06-01: Putting the land onto the battlefield or casting the card is not optional.
2011-06-01: If the player is unable to put the land onto the battlefield (this is rare) or cast the spell (perhaps because there are no legal targets available) as the triggered ability of Omen Machine resolves, the card simply remains in exile.