Oracle

Sorcery 

Spell mastery - If there are two or more instant and/or sorcery cards in your graveyard, you may cast Swift Reckoning as though it had flash. (You may cast it any time you could cast an instant.)
Destroy target tapped creature.

Tournooi-info

Legal in: Vintage, Legacy, Modern, Commander

Officiele rulings

6/22/2015
The number of instant and/or sorcery cards in your graveyard matters only as you begin to cast Swift Reckoning. Once it’s cast, that number doesn’t matter and will have no effect on Swift Reckoning resolving.

6/22/2015
Check to see if there are two or more instant and/or sorcery cards in your graveyard as the spell resolves to determine whether the spell mastery ability applies. The spell itself won’t count because it’s still on the stack as you make this check.

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