Spells and abilities are countered on resolution if all of their targets are illegal when they attempt to resolve. If a spell has multiple targets and at least one of them is legal when it goes to resolve, the spell will resolve and do as much as possible. However sometimes spells seem like they have multiple targets, but do not.
Chandra’s Outrage targets a creature and when it resolves it deals four points of damage to that creature and two to that creature’s controller. The spell may affect a creature and a player, but it only targets one of them. Because of this, the Chandra’s Outrage will become countered on resolution if the targeted creature is not a legal target when the spell attempts to resolve.