Shadwen

After completing the game, return to the main menu and use the Chapters menu to replay Level 15 (Rivendon Castle), Checkpoint 4 (The Dining Hall). This time around you need to kill at least one guard and make sure Lily sees you do it (or sees the body), but do not kill the king when prompted. When killing guards make sure other guards don’t discover the body, otherwise they will raise an alert that will trigger a game over. As long as you hide the body once Lily sees it you are good to go. At the end of the level, choose to not kill the king.