Fans are in for a big surprise when "Arrow" season 5 returns from its brief hiatus.

Prometheus (Josh Segarra) has been plaguing Team Arrow all season long, and they have yet to put an end to this psychotic villain, whose goal is not to terrorize the city but to break Oliver Queen (Stephen Amell), also known as the Green Arrow, emotionally and psychologically.

It seems like Oliver will do whatever it takes, and use everything and everyone he has, to take down Prometheus. He even resorted to asking help from the Russian mafia, Bratva, which did not end up well. Recently, executive producer Wendy Mericle has revealed that during the remainder of "Arrow" season 5, viewers will be even more shocked by whom he will be working with in order to defeat this season's big bad.

"The alliances are going to be very surprising," Mericle told Entertainment Weekly. With this said, it looks like Oliver's questionable decisions do not end with forming an alliance with Bratva. The upcoming episodes are also said to be very emotional. She added, "It's going to be all about Oliver's family, but not the family we're thinking of right now. It's going to end in a giant explosion, but not where we think it's going to end, and the emotional punch is going to be bigger than the actual physical part of the bombs going off."

According to Comic Book Resources, there is a possibility that these surprising alliances could come in the form of the show's previous villains. The publication sees the Black Siren, Laurel Lance's (Katie Cassidy) Earth-2 doppelgänger, as a candidate since it has recently been announced that Cassidy is coming back to the show as a regular in the next season. Another possible shocking ally could be Talia al Ghul (Lexa Doig), the daughter of the late Ra's al Ghul (Matt Nable). Although, as to how this alliance with Talia will play out since she holds a grudge at Oliver for killing her father, viewers will have to wait to find out.

"Arrow" season 5 returns on Wednesday, April 26, at 8 p.m. EDT on The CW.