If Brynhir is played and resolves first, does it prevent opponents from playing their cards when Promising Future is played afterward?

Ruling: No, Brynhir does not prevent opponents from playing cards from Promising Future when played in this order. When Brynhir resolves before Promising Future is played, her ability is active and prevents opponents from playing cards.

Sequence:

• Play Brynhir and let it resolve
• Play Promising Future
• Opponents look at the top 5 cards and banish one
• The banished card stays banished because they cannot play it due to Brynhir's effect

Nuances:

• If Brynhir were played after Promising Future, it would not work because all cards from Promising Future would already be pending on the chain before Brynhir's trigger could register
• Opponents still get to look at and banish a card, but cannot play the banished card