Path of Peace

• WWizards of the Coast2018-03-16
  Official Ruling
  You are a creature's owner if the card representing it began the game in your deck, or if it's a token that entered the battlefield under your control. If Path of Peace targets a creature that you own but an opponent controls, you'll gain 4 life.
• WWizards of the Coast2018-03-16
  Official Ruling
  If the target creature is an illegal target by the time Path of Peace tries to resolve, the spell doesn't resolve. No player gains life.

Rulings via Scryfall