Strength of the Sword 3

In order to perform a finishing move on an enemy, you have to significantly lower their health. Once they are near death, a icon will appear above their head. Run up to them, spam and a short animation will play out where you brutally murder the enemy. You only have to do this 11 times so you will likely acquire it naturally during gameplay. Each time you perform a kill with a finishing move, you will get a notification at the bottom of the screen saying "FINISHING MOVE".