Arrow: 7 Plot Threads The Show Totally Abandoned
6. Vigilante
Vigilante showed up in the show's fifth season as a, well, vigilante who just so happened to hate other vigilantes. And, with that, he attempted to take down Oliver and even brought the fight to Prometheus.
Though his name in the comics was Adrian Chase, the show pulled a bait-and-switch, revealing that to be the true identity of Prometheus - meaning that Vigilante's identity remained a secret throughout the remainder of the fifth season following his apparent demise.
His return in Season 6, however, wasn't nearly as successful, as it turned out that he was really Vincent Sobel - the former partner and lover of second Black Canary Dinah Drake whom we had only met in a single flashback episode in Season 5. Not only was this reveal completely undercut by the fact a different actor was playing Vinnie (rendering us even more confused in the moment), it clearly wasn't the initial plan for the character since he debuted before Dinah and crossed paths with her throughout Season 5 without revealing who he was.