Dance with Calamity is a rare Sorcery card from March of the Machine Commander (MOC), collector number 116. Current market price: $3.27, TCGplayer market prices via Scryfall.
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.