The assassin strikes quietly and with intent, so dream books read the figure as a hidden threat to your plans or standing, or as the urge to cut something out of your life with precision.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.