Heralds of Tzeentch

You exile the cards face up. All players will be able to see them.

If a spell with cascade is countered, the cascade ability will still resolve normally.

If you cast a card "without paying its mana cost," you can't choose to cast it for any alternative costs. You can, however, pay additional costs. If the card has any mandatory additional costs, you must pay those to cast the card.

A spell's mana value is determined only by its mana cost. Ignore any alternative costs, additional costs, cost increases, or cost reductions.

Two new cards in this set give the next spell you cast cascade. This means that the next spell you cast gains cascade as you begin to cast it by putting it on the stack, and the cascade ability will trigger when you finish casting that spell.