‘Arrow’ season 5 spoilers: Who could be hiding behind Prometheus’ mask?

The fifth season of "Arrow" has started on The CW and it poses a great mystery to solve. Fans are now anxious to know who could be hiding behind this season's new villain named Prometheus? Here are various speculations about who could possibly fit the antagonist's identity.

First on the list is Tommy Merlyn (Colin Donnell). Multiple reports believe that Tommy is the strongest fit for the new villain as he has quite significant reasons to take revenge on Oliver Queen (Stephen Amell).

Tommy was first introduced in the first season as Oliver's best friend. They were the best buddies until the latter started dating Laurel (Katie Cassidy), the ex-girlfriend of the former. This arc is speculated to be one possible bitter plot of revenge as Tommy did not like the idea, and was quite jealous too.

Also, Tommy's hatred could push him to the blame Oliver for the death of Laurel and even his own demise. Although his character has already died in season 1, fans believe that anything can happen in superhero series, so it is possible that he will return, yet no longer as an ally, but as the new mysterious nemesis.

However, the International Business Times noted that the only constraint is that Donnell still has a regular gig in "Chicago Med." It would be difficult for the actor to juggle his schedule as his current show is filming in Windy City, while production of "Arrow" is in Vancouver.

Fortunately, there is still a chance for Donnell to reprise his role in "Arrow" as Prometheus will not likely unmask himself this early, which could give time for the actor to complete his shootings in the other show and be able to come back as Tommy later in season 5.

Another candidate for the Prometheus identity is Slade Wilson (Manu Bennett), aka Deathstroke. He is also known to have many reasons to eliminate Oliver.

Moreover, another theory has surfaced pointing to Billy Malone (Tyler Ritter), Felicity's (Emily Bett Rickards) boyfriend, who was shown to have tipped off the Green Arrow. His gesture could have been rooted from an anger in the past, where someone close to his heart must have been killed off by the protagonist in the past.

"Arrow" season 5 airs every Wednesday at 8 p.m. on The CW. Check the promo video for episode 4 titled "Penance" here.