Casting the copy of the prepared spell works just like casting any other spell. You have to pay its cost, and you have to follow the timing rules put in place by its card type. If it's a sorcery like Rampant Growth, you can cast it during your main phase if the stack is empty. If you cast a prepare spell from exile, the prepared creature becomes unprepared, meaning it loses the prepared designation.

The ability word opus highlights triggered abilities that trigger whenever you cast an instant or sorcery spell. Each opus ability has an initial effect and an additional or alternative effect if you spent five or more mana to cast the spell that caused the opus ability to trigger.

Du kannst eine Karte mit Rückblende aus deinem Friedhof wirken. Falls du dies tust, bezahlst du ihre Rückblende-Kosten, anstatt ihre Manakosten zu bezahlen. Rückblende ändert nicht den Zeitpunkt, zu dem du den Zauberspruch wirken kannst, d. h., eine Hexerei mit Rückblende kann trotzdem nur während deiner Hauptphase gewirkt werden. Außerdem ändert das Wirken eines Zauberspruchs mit Rückblende nicht seinen Manabetrag. Der Manabetrag basiert immer auf den Manakosten eines Zauberspruchs, auch falls du alternative Kosten bezahlst, um ihn zu wirken.

Paradigm is a new keyword that appears on a cycle of sorceries and gives them true staying power. The first time a particular spell with paradigm resolves for you, you exile it. From that point forward, at the beginning of each of your first main phases, you may cast a copy of it without paying its mana cost. Casting each of these copies is optional, and you'll have the opportunity to cast one on each of your turns no matter what happens to the previous ones.