Shadwen

In order to unlock this trophy you need to kill all the guards in the game (with the exception of Level 1) and kill the king at the end of the game.

While this will likely be easier than your no-kills playthrough, you should keep in mind that you will need to dispatch each guard individually, from behind, and out of sight of the other guards. You cannot just run up to a group of 2-3 guards and kill them Assassin’s Creed style, as they will raise an alarm (or kill you) and cause a game over. The same applies to guards who discover bodies, so be sure to hide bodies while you are dispatching the other guards. In the event that you are seen, or a body is discovered, just rewind time to fix things. In areas where 2 or 3 guards are grouped together, you can use sound or the environment to distract individual guards so that they will investigate and you can take care of them out of sight of the others. The most important thing to remember is that you must back-stab every guard (or drop from above on the heavily armored ones) in order to kill them. Frontal assault will not work and will only result in a game over. As always, you can rewind time if you are seen.

As you progress through the levels, be sure to kill every guard on the level (see the individual trophy descriptions for the number of guards on each level). For most levels the guards are easy to find and cannot be missed, but there are a couple of levels where there are guards are inside open buildings or in areas not in the direct mission path, so before exiting an area go back to double check that you didn’t miss anyone. At the end of the game, you will be asked how you want to deal with the king, and you should choose to kill him.