Thirst for Blood(Dark Blood)
As a swift action, you grant yourself an additional turn at the end of the round. You can only take 1 standard action during this extra turn (effects such as haste that grant you additional actions in a round have no effect). After using this extra standard action, you become staggered for 1 round. After using this ability, it becomes expended for 5 rounds.
Capstone Empowerment: After using the extra action granted by thirst for blood, you are fatigued for 4 rounds instead of staggered for 1 round.