Arrow Season 6: 10 Major Predictions
3. Vigilante Is...
While the identity of Prometheus was eventually revealed as Adrian Chase, the person under the Vigilante mask was kept a secret, with the character disappearing for the end run of Season 5.
The decision to focus more singularly on Chase and Oliver made sense, and means that the identity of Vigilante is still up in the air for Season 6, with a few key suspects (as it's someone we've been introduced to previously).
Like with Prometheus, it probably isn't Tommy Merlyn, largely on account of the fact actor Colin Donnell is still a regular on Chicago Med. Captain Pike has been the most prevalent theory, since they went MIA around the same time, but Pike doesn't have the strong personal connection the showrunners have spoken about. Nor does the other hot favourite, Curtis' husband Paul (outside of Curtis, obviously, and that's not a connection that would blow fans' minds).
Dorian Chase, as a brother of Adrian from the comics, is a good possibility in that it could bring Josh Segarra back if they made them twins (he doesn't have any other projects at the moment), and plays on the original expectations for who Vigilante is, while he'd have a similar connection to Oliver as Adrian did. Of course, the fact that Adrian Chase wasn't Prometheus' real name hurts this theory too. Floyd Lawton would be pretty cool too, since he's been a great guest character in the past, and would be a fairly big surprise.
All of this conjecture is to say... It's going to be Paul, isn't it?