Suppose that my opponent activates Nicol Bolas, Dragon-God's third loyalty ability, which reads:
Each opponent who doesn't control a legendary creature or planeswalker loses the game.
As the ability resolves, I control no legendary creatures, and the only planeswalker I control is either Personal Decoy or a copy of any other planeswalker created by Spark Double. What happens? In other words, should the text be interpreted as
who doesn't control (a legendary creature) or ([a] planeswalker)
in which case I don't lose, or
who doesn't control a legendary (creature or planeswalker)
in which case I do lose?