Master the Way

• WWizards of the Coast2014-09-20
  Official Ruling
  Use the number of cards in your hand after you draw the card to determine how much damage Master the Way deals to the target permanent or player. (Remember that Master the Way is not in your hand; it’s on the stack.)
• WWizards of the Coast2014-09-20
  Official Ruling
  If the permanent or player is an illegal target as Master the Way tries to resolve, Master the Way won’t resolve and none of its effects will happen. You won’t draw a card.

Rulings via Scryfall