"Arrow" season 4 is setting up some changes, according to Vinereport. The most notable change will be the lighter tone as Oliver Queen will reinvent himself as a happier superhero instead of the dark and brooding vigilante that was depicted in the first three seasons, which is why fans have been speculating that he will now be known as Green Arrow. 

This was further cemented when actor Stephen Amell reminded fans that Roy Harper, played by Colton Haynes, was the one who publicly declared himself as the vigilante known as "Arrow." 

"Roy outed himself as the Arrow, so if I were to re-create the suit and go out, it would undo all of the sacrifice that he made," Amell explained in the report. "So the Arrow persona, for better or for worse, it can't exist anymore." 

This means that if Amell is going back to save Starling City from criminals, then he will have to don a new suit. With a lighter personality, it is very possible that fans will get the Green Arrow presented in the comic books. 

Season 4 will also introduce the villain known as Damien Darhk. Damien was once a member of the League of Assassins and was also a friend of Ra's al Ghul until the latter became the new leader of the League. Damien left and formed his own criminal organization known as H.I.V.E. 

H.I.V.E. has made its existence known since season 2 of the show. The organization was responsible for hiring Deadshot to kill John Diggle's brother and is allegedly behind many of the events that occurred in the series thus far. Several members have been revealed but Damien himself has not yet made an appearance in the series. 

In the comic book source material, Damien Darhk is also known as a highly sophisticated genius who has also attained the peak of human physical strength, making him one of the most powerful foes that Team Arrow could possibly face.