Now since we learned that Adrian Chase was Prometheus not Vigilante as previously assumed the question still remains: Who the f*** is Vigilante? There aren't too many suspects as to who he can because he clearly doesn't know Green Arrow's secret identity as he only seeks to kill him so he won't interfere in his own crusade, yet tried to kill Oliver Queen for being a corrupt mayor. The producers have stated that Vigilante is a character already familiar to the audiences and this made me think it was Roy Harper or Deadshot. However the odds of Deadshot returning are very low and apparently Colton Haynes has been cast in American Horror Story so he's out too. I read a while ago that Josh Segerra is rumored to reappear in Arrow next season and this makes me think: Could Vigilante be the real Adrian Chase still played by Josh Segarra and Simon Morrison was using his identity? Of course there'd have to be an explanation as to why Adrian and Simon look exactly the same so I think they may be twin brothers. Below is an idea of how Adrian and Simon cold be twins and what Adrian's motives for being Vigilante could be:
Simon and Adrian were born to the same mother but Adrian was given up for adoption to the Chase family and raised with them, and his foster brother named Dorian. While both twin-brothers knew each other and their father Justin Claybourne, Adrian hated the monster he was whereas Simon loved him which often brought the brothers into conflict. As adults Adrian became a lawyer to end his father’s corruption whereas Simon followed into his father’s footsteps and in 2012 Claybourne was killed by Oliver. While Adrian was glad that his father’s evil had been ended Simon became vengeful yet both brothers agreed that the Hood is a serial killer who will only create more evil. However Adrian hated the fact that he admired him somewhat as he ws bringing an effective form of justice to a corrupted city.
Shortly after Simon vanished and all traces of his existence were erased from the internet while Adrian continued to climb his way up the ranks in the DA’s office and became an assistant district attorney. In 2016 however Adrian suffered the loss of a close friend and ex-girlfriend who he was still in love with, who was also a lawyer and was considered to be the new district attorney, and upon learning her biggest secret was inspired to honor her memory by bringing justice both in court and in the streets same way she, Dinah Laurel Lance, did. However Adrian also came to blame Green Arrow for Black Canary's death, believing that if he had killed Damien Darhk when he had the chance she’d still be alive and swore to make up for Green Arrow’s mistakes and honor Black Canary’s memory and became “Vigilante”.
Shortly after his crusade as Vigilante began Adrian finally climbed to the top and became the district attorney of Star City. Before he started working however he was approached by Simon who revealed he’d kidnapped his foster brother Dorian and threaten to kill him, having him kept in a room rigged with explosives connected to a dead-man switch triggered by Simon’s death, unless Adrian let Simon take his place in the DA’s office. With no choice, Adrian agreed and watched as Simon started living his life but Simon allowed him to keep operating as Vigilante but if his methods got too extreme he'd send his "associate" Prometheus after him. Months later Adrian’s reputation was ruined when Simon, using Adrian’s name, was exposed as Prometheus himself. Without evidence to prove his own existence since Simon was using Adrian's name in public eye while all traces of Simon Morrison's existence had been erased, Adrian has been stuck in hiding ever since. Even worse Simon killed Dorian anyway and before Adrian could find him Simon committed suicide on Lian Yu and Adrian was left with nothing but his grief and anger.
I think it was Laurel’s death that forced him over the edge because not only did Vigilante not appear until after her death but in 5x15 there was a moment when after Dinah attacked him he looked right at her, and it looked as though he recognised her, and from a glance Dinah does kinda bare a slight resemblance to Laurel (which is why I think she's Laurel's time displaced grandmother). Also if I’m right and the real Adrian was also an attorney then chances are he and Laurel knew each other, and Laurel herself admitted that she had a habit of dating bad boys. It would also give more of a personal connection between him and Oliver and would kinda make Vigilante a foil of Oliver as he too was driven into killing again because of Laurel’s death, but of course Vigilante doesn't have the same restraint as Oliver becaues he likley doesn't have anything else worth fighting for unlike Oliver.So this is just an idea but I’d love if Vigilante was somehow the real Adrian Chase and is still played by Segarra because I did like him as Prometheus but I did also like the way he portrayed him initially as a driven and no-bullshit lawyer willing to use more extreme methods of achieving justice if needed, but still had a charming and friendly personality despite clearly having been affected by a troubled past. I’d like it if somehow Simon was literally copying Adrian and this is what the real Adrian is like and this is how he interacts with Oliver, though obviously with a bit of added tension. If Prometheus really did just kill someone (lets’ pray for Felicity!) then it would be interesting seeing Oliver being forced to interact with a man who looks exactly like the man who caused him so much pain, similar to how Barry was forced to interact with Earth-2 Harrison Wells after witnessing Eobard Thawne (using Harry's Earth-1 counterpart’s appearance) cause him so much misery. It would give Oliver an interesting story if he tried to help Adrian and stop him from falling into insanity like his deranged twin-brother.