Dance with Calamity (Extended Art) [March of the Machine Commander] Human Soldier Scout You may look at and

You may look at and play that card for as long as it remains exiled

and you may spend mana as though it were mana of any color to cast it

When Worldspine Wurm is put into a graveyard from anywhere

Feeding Grounds

Dance with Calamity (Extended Art) [March of the Machine Commander] Human Soldier Scout You may look at andSet: March of the Machine Commander Type: Sorcery Rarity: Rare Cost: {7}{R} Shuffle your library. As many times as you choose, you may exile the top card of your library. If the total mana value of the cards exiled this way is 13 or less, you may cast any number of spells from among those cards without paying their mana costs.