For this achievement you will need the Eagle Harass skill and the Enhanced Predator Bow skill. Just find any enemy you would like ( I used a random guard at the Ptah temple in Memphis) and take control of Senu then just target the enemy and hit the harass button as soon as you target the guy and have Senu harass exit Senu and use a predator bow and control the arrow into the enemies head. I tried getting this achievement without controlling the arrow and none of the arrows or other bow types worked not sure if this is a glitch or by design.