There are many important moments in the story, but the most crucial—called “story spotlights”—are shown on cards. These cards have the Planeswalker symbol in their text box; this symbol has no effect on gameplay. You can read more about these events in the official Magic fiction at http://www.mtgstory.com.

If the target creature or planeswalker is an illegal target by the time Vraska’s Contempt resolves, the entire spell doesn’t resolve. You won’t gain life.