How to get the Return to Sender achievementYou first need to have upgraded your arrow deflection skill, preferably to the maximum. Then you need to find either a place with three archers, or an area with a respawning one. This guide will show you where you can find three archers in close vicinity and how you can kill them by deflecting their arrows.
Travel to the abandoned camp marked on the map below. When you approach it, you will be attacked by three swordsmen and an archer. Kill the swordsmen, then prepare to deflect the archer’s arrows. Keep the distance from the archer (so that he will draw his bow), then press the parry button just as the arrow is about to hit you. That way the arrow will deflect off of your weapon and fly right back to the archer. To see it in action, check the video up top.
Now move to the left and head for the jetty. An archer is standing there, kill him using the same method as before (parry just before the arrow is about to hit you). Once he’s dead, head right to a cottage in the distance. There are two swordsmen and an archer in front of it. First kill the swordsmen, then the archer, in the same way as before. Killing the third archer will get you the Return to Sender trophy. Congratulations!