Dream Strix

• WWizards of the Coast2021-04-16
  Official Ruling
  If Dream Strix becomes the target of a spell, it will be sacrificed before that spell tries to resolve. If it is the only target of that spell, it will be removed from the stack rather than resolving, and no part of its instructions will be performed.
• WWizards of the Coast2021-04-16
  Official Ruling
  If instructed to learn, you may do nothing. Discarding a card and putting a Lesson card into your hand are both optional.
• WWizards of the Coast2021-04-16
  Official Ruling
  If you bring a card into the game from outside the game in a Sealed Deck or Booster Draft event, you may select only a card that is in the card pool that you built your deck from.
• WWizards of the Coast2021-04-16
  Official Ruling
  If a card is brought into the game from outside the game, it will stay in the game until it ends or until its owner leaves the game, whichever comes first.
• WWizards of the Coast2021-04-16
  Official Ruling
  If you bring a card into the game from outside the game in a Constructed tournament (or a Constructed game played under tournament conditions), you may select only a card from your sideboard. In casual Constructed games, the card comes from your collection.

Rulings via Scryfall