Arrow Season 4 has witnessed the death of the Black Canary (Katie Cassidy). Many were unhappy by her demise above all because Canary was Arrow's original colleague. Now it is most likely that Oliver Queen is the next to meet his demise.
Full article here: http://www.itechpost.com/articles/49244/20161102/arrow-season-5-episode-5-spoilers-oliver-queen-will-die-human-target-to-replace-him.htm