By using the teleportation effect of the walker shield and sword, you get teleported to the same coordinations like your atacker. That results in appearing on one of the enemys sides, based on the direction you (and your enemy) moved at the moment of teleportation.
Because you are normaly walking towards your enemys, you will pop out behind him, but looking into the wrong direction. Mobs will instantly turn around and atack again, but the player has to orientate first, which makes the effect kind of week right now.
If you would be ported to a set location based on your enemy, like 1 block in front of him or even behind him with 180 degree changed, then it would actually be really helpful.