7) Earth-2 Oliver Queen
Season 5 of Arrow has introduced us to a new Laurel Lance in the form of Black Siren, a villain from Earth-2. It was The Flash which first tackled the concept of alternate realities, but outside of that different version of Laurel, the series has remained largely unaffected. Until now, maybe? On Earth-2, Laurel turned to villainy after Oliver was killed on the Queen’s Gambit. His father Robert then became the Arrow on his world’s Star City, but what if Oliver survived the same way as Sara Lance did on Earth-1?
Regardless of how he’s ended up in the same world as the Green Arrow we all know and love, a deranged Oliver becoming Vigilante is an interesting concept and one which has a lot of potential if he ultimately decides to try and replace his Earth-1 counterpart. Heck, it could even be Robert who’s beneath the hood.
Either way, an Earth-2 character being Vigilante opens the door to a lot of new storytelling possibilities in the same way Black Siren’s unexpected arrival has.