Board Thread:Arrow discussions/@comment-9346948-20161110011241/@comment-27608733-20161111100758

Quentin as Prometheus actually makes sense, even without split personality or Barry altering the timeline. When Sara "died" on the Queen's Gambit, Quentin's hatred for Oliver started to grow. He trained himself to one day eventually kill Oliver. However, when Sara returned, he decided not to kill Oliver but to help Sara and The Arrow instead. When Sara died again, Quentin decided to keep on training and regained his hatred for Oliver. And then when he discovered that Oliver was The Arrow, he wanted to hunt him down once and for all, but didn't have evidence as Roy jumped in. Afterwards, he infiltrated Team Arrow and as Laurel died, his hatred for Oliver grew stronger and eventually, he finished his training and became Prometheus.