"The leader of a military outpost in the north-west is a confirmed Templar. Kill him."
Head to the Northwest from the pigeon coop to reach the rocky outpost the military in the area is using. Go past it to the adjacent Rocks that give a good view of the area. Go to the Southeastern edge of them. You will have a perfect view of your target. Shoot him with either your pistol or a Berserk Dart to kill him quickly.
If you want to get closer, then creep up the Northern side of the area. Use the Stalking Zones to close the distance to your target by luring in the nearby guards one at a time.