Can I reveal and play a Reaction card (like Consult the Past) during my opponent's turn if they just played a unit and passed without creating any closed states?

Ruling: No, you cannot play a Reaction during your opponent's turn unless you get priority. Priority is only given during triggered abilities, other abilities, showdowns, or end-of-turn effects (like those from Annie or Sona legends).

Nuances:

• Simply passing the turn after playing a unit does not create a closed state or give you priority
• You can reveal the hidden card as soon as it becomes your turn