Flying
Whenever a creature with flying attacks, you may draw a card.
"Your mind is too filled with foolish concerns to hear the subtle whispers that the breeze brings."
(13/07/2018)
It doesn't matter who controls the creature with flying or which player or planeswalker that creature is attacking. Windreader Sphinx's controller is the player who may draw a card.
(13/07/2018)
The creature must have flying immediately after being declared as an attacking creature in order for Windreader Sphinx's ability to trigger. For example, attacking with Kitesail Corsair will cause the ability to trigger, and attacking with Pegasus Courser and a creature without flying will cause the ability to trigger only once.
(13/07/2018)
Windreader Sphinx's ability will trigger when it itself attacks.
