Greater Called Shot

You can make multiple called shots where others could land but one. 
Prerequisites: Improved Called Shot, BAB +6 
Benefit: Whenever you make an attack, you can choose to replace that attack with a called shot. You can make multiple called shots in a single round. Each additional called shot after the first made in the same round takes a –5 penalty. You no longer take a penalty to your attack roll when you are making a called shot against a target who has moved more than 5ft in their previous turn. In addition, a called shot that a called shot that deals a moderate critical effect is bumped up to a serious critical effect. 
Normal: Only one called shot can be performed per turn and moderate critical effects are not changed to serious critical effects on a successful called shot.