Dazzling Sphinx
Creature — Sphinx
Flying
Whenever this creature deals combat damage to a player, that player exiles cards from the top of their library until they exile an instant or sorcery card. You may cast that card without paying its mana cost. Then that player puts the exiled cards that weren't cast this way on the bottom of their library in a random order.
Oriana Menendez
Magic Online Promos (PRM)
• #90030Rulings
Dazzling Sphinx's triggered ability lets you cast the exiled card during the resolution of the ability. It doesn't allow you to wait and cast the card later.
(wotc • 2021-04-16)
If the exiled instant or sorcery card has an {X} in its mana cost, you must choose 0 as the value of {X}.
(wotc • 2021-04-16)
You may choose not to cast the instant or sorcery card that you exiled. In that case, it will be put on the bottom of the library with the rest of the exiled cards.
(wotc • 2021-04-16)
Rulings
Dazzling Sphinx's triggered ability lets you cast the exiled card during the resolution of the ability. It doesn't allow you to wait and cast the card later.
(wotc • 2021-04-16)
If the exiled instant or sorcery card has an {X} in its mana cost, you must choose 0 as the value of {X}.
(wotc • 2021-04-16)
You may choose not to cast the instant or sorcery card that you exiled. In that case, it will be put on the bottom of the library with the rest of the exiled cards.
(wotc • 2021-04-16)