SPOILER WARNING for the season five finale of Arrow.

Season five of The CW's Arrow left us with one hell of a cliffhanger, one that will have us agonizing over the next four months as we wonder just who will make it out of this one in one piece. As we start taking in odds and bets on which characters will come back alive, we also look beyond the resolution of this cliffhanger, and at just what exactly season six will bring to the table as far as main stories go. The series has concluded its original five-season plan, so season six is headed into uncharted territory.

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Now that the flashback formula has come full circle and has been put to rest, we don't know what shape the next season will take yet, or if the series will live on beyond that point. With season three and four both seen as disappoints by a lot of fans, season five was widely lauded as a great return to form for the CW series. Season six is a mystery, but there are ways to ensure the show's prosperity and longevity. Join us today as CBR takes a look at 15 possible ways for Arrow to have its best season yet and live on for season seven.

15 SLADE WILSON BACK IN THE CAST

Season five of Arrow ended on a particularly strong note, with a finale that brought back so many old fan-favorites to face off against Adrian Chase. Chief among those returning characters was none other than Manu Bennett's Slade Wilson, aka Deathstroke. A highlight and beloved character in the first two seasons of the show, every fan was glad to see Slade come back to the Arrow fold.

And if Bennett proved anything once more, it was that his character belongs on the show. He instantly elevates every scene he is in and helps make Oliver Queen a better, stronger character. With Slade's new outlook and mission on life, season six would be the opportune time to bring him back full time as a recurring cast member, so that Slade can finally leave the island and search for his son.

14 FLASH-FORWARDS

Now that the show has explored all five years of Oliver Queen's time on (and off) the island, the series will have more time on its hands. Time to tell more stories, and maybe take even more risks. A few episodes throughout the series have shown that they worked well by telling stories set only in the present, but to keep things interesting, Arrow could borrow a page from the LOST playbook and introduce flash-forward segments.

If the flashbacks were set five years back, then forwards could be set five years ahead. With Oliver's son William the only character we know for sure is alive right now, these windows into the future could see the Green Arrow, abandoned by his friends and teammates, training his son to become a vigilante. This could start a new story that would propel the series for another five years as we look for answers.

13 GET RID OF MR. TERRIFIC

Echo Kellum was brought in the fourth season of Arrow as Curtis Holt, a tech-genius who, over the course of his appearances, would become a new version of the DC Comics character Mr. Terrific. As a member of Team Arrow, Curtis is neither the most efficient fighter, nor is he the best hacker compared to Felicity. For those reasons alone, it has become increasingly apparent that Mr. Terrific is not getting his rightful due on Arrow.

Season six would do well to get rid of the character. Kellum is a great actor and he brings some nice comedic relief to the series, but Mr. Terrific would be far better used on a series like DC's Legends of Tomorrow. Curtis doesn't have much of a role to play on Arrow, and his departure could open a spot on the team, one that could be filled by another character waiting his due...

12 BRING ROY HARPER BACK

Roy Harper was introduced in the first season of Arrow, trained throughout most of season two and finally earned his mask and bow in season three. But almost as soon as Roy had his costume and a codename of his own, he took the fall for the Arrow and left the show to start a new life. However, comic book readers know that Roy has a lot of story left to tell.

Speedy/Red Arrow/Arsenal is a character that has come into his own and become a crucial member of the Teen Titans. He lost an arm, gained a mechanical new one and overcame his anger to become a formidable hero. If Roy were to come back in season six, we could finally see the character go through those crucibles, and become a real hero all on his own.

11 A ROADTRIP WITH HAWKMAN

One of the more famous Green Arrow comics saw the emerald archer team-up with Green Lantern as the two traveled throughout the United States rescuing people along the way in the aptly titled Green Lantern/Green Arrow series by creators Dennis O'Neil and Neal Adams. For its sixth season, Arrow could look to this comic book for a bit of inspiration.

After the tragedy of Lian Yu, Oliver Queen could see it apt to travel across the country in a bid to reconnect with the people. It seems unlikely that the CW will ever introduce a Green Lantern in their television universe, so instead Oliver could share the road with another superhero he has a long and difficult relationship with: Hawkman. A new version of Carter Hall could not only redeem the Legends of Tomorrow character, he could also help Oliver on his road to rediscovery -- and that road could lead Oliver to...

10 SEATTLE

In Green Arrow: The Longbow Hunters comic series by Mike Grell, a series that helped inspire the Arrow television show, we saw Oliver Queen relocate to Seattle, Washington. Ever since then, Seattle has been a city as closely associated with the character as Star City. In fact, it is the city the character has operated in in DC's New 52 as well as Rebirth.

After five seasons of saving Star City, the time could be right to help another city out there. Season six could then see Oliver Queen let go of his home city and choose to start fresh somewhere else. This would not only allow us to see a Green Arrow working on his own again for a little while, it could also set the stage for the arrival of a reformed Black Siren and the formation of a new dynamic duo.

9 AN ACTIVIST GREEN ARROW

Green Arrow is a character well known to be an activist. A man who fights for the little guy. A man for the people, just like Robin Hood. We have seen a bit of that trait back in season one when Oliver was taking care of the corrupt in his city, but over the years, we have seen more and more of Green Arrow the crime-fighter, and less the activist.

As Mayor of Star City, Oliver set out to help his city in a different way, but only ended up at the mercy of Adrian Chase. In season six, we could see the Mayor Queen storyline come to a close with Oliver leaving Star City and helping those in need on his road trip, as well as in Seattle. And to help fund his new venture to better help the people, he would surely need some money.

8 Q-CORE

With The New 52 relaunch in the comic books, we saw Oliver Queen operating in Seattle, and at the head of a new division of Queen Consolidated called Q-Core. Oliver's family company featured heavily in the first two seasons of the show, but it got consumed by the arrival of Ray Palmer and Palmer Tech in Star City. Queen Industries is now gone, and Oliver Queen isn't a millionaire anymore.

But, if Oliver saw it crucial to his cover be at the head of a company again, if he would be in need of revenue to help everyone, he could choose to start a new company in Seattle. Just like in the comics, Q-Core could become a part of the mythology of the show, and it would allow us to see Oliver return to his roots as he duels his Green Arrow identity with that of his job as a CEO.

7 CHARACTERS WITH SEPARATE STORYLINES

As more members joined Team Arrow throughout seasons three, four and five, there was no denying the fact that the Arrowcave was getting crowded. But while writing off characters isn't necessarily always the answer, separating them could be. In season five, we saw Felicity go through her own side-story with Helix. The same goes for Diggle, who saw himself imprisoned for a time.

For season six to work, it needs more stories that take these characters that fans have come to love on their separate journeys to highlight them on their own. It allows for character growth, and would make the scenes where we see all of them united and fighting side-by-side all the more exciting and spectacular. And key among those new stories would be one that could put Diggle in an entirely new position.

6 JOHN DIGGLE: A.R.G.U.S. DIRECTOR

John Diggle is a great, fan-favorite character. He is dependable and is as strong as his moral compass. But sadly he is a character that has been sidelined from time-to-time as the cast of the series continues to grow. It would then be a departure -- and an interesting new beginning -- for the character to see him take his wife Lyla's job as the head of A.R.G.U.S., something he is clearly more than qualified to do.

Diggle would be propelled in his own storyline, and his role on the series would drastically change. We have seen him clash with his wife over how A.R.G.U.S. should operate, and this could be the chance not only to see him try to steer the ship, but also organically take him away from the Arrowcave. With A.R.G.U.S. at his disposal, Diggle could be a great ally, partner and leader -- a position that he was groomed for.

5 BRING HUNTRESS BACK AS A HERO

Introduced very early on in season one, we saw Helena Bertinelli's evolution and creation into the Huntress. But she turned out different than her comic book counterpart. Brutal and hellbent on revenge, we last saw her in season two, imprisoned, ready to make a change and embrace another way of life. And we haven't heard from her since.

But season six could be the place where we see Huntress resurface as the hero she was always supposed to be. With her quest for vengeance now concluded, Helena could embrace what Oliver had taught her so long ago and be inspired by the Green Arrow's heroics to put her costume back on and this time fight to help protect those in need. This could offer a nice payoff to something that was introduced a long time ago.

4 THE BIRDS OF PREY

Felicity Smoak is a divisive character. She was a great addition to Team Arrow, but others hated her relationship with Oliver Queen. No matter where you fall on that line, everyone can agree that Felicity would be right at home as the brains of her own operation. With Oliver off on his own (and Black Siren) in Seattle, Felicity could see it upon herself to form a new team: the Birds of Prey.

In the spirit of sending the characters on their separate storylines, Felicity could team up with Dinah “Black Canary” Drake, Huntress and maybe even Thea Queen for an all-female team protecting the streets of Star City. Throw in Wild Dog into the mix as the odd man out, a dog in a team of birds, and you have the makings of some very entertaining adventures.

3 THE RISE OF SOLOMON GRUNDY

Back in the early days of season two, before Deathstroke and his army, we had Brother Blood and his Acolyte, Cyrus Gold. A man destined, in the comic books, to become the super-villain zombie monster known as Solomon Grundy. The stage seemed all but set for Grundy to appear when we saw Cyrus Gold killed in a blast that covered him in Mirakuru and left his skin grey. But that was the end of it.

Now is the perfect time to payoff a setup that was made a long time ago. Solomon Grundy's rise from the grave could be one of the season's big threats, and he could be a very different villain from those who have come before. Besides, it would allow Oliver to once again deal with a threat that he created, and show us how he has evolved from season five.

2 THE OUTSIDERS WAR

The Outsiders War is a famous, if recent, storyline to Green Arrow comic book readers. It was a spectacular story that brought a lot of new mythology to the character with the introduction of seven ancient clans based on old totem weapons: Axe, Fist, Shield, Sword, Spear, Mask and Arrow. A lot would have to be changed from the comics, but these clans could slowly be revealed through the season as they emerge as the one and true threat.

After four seasons of singular villains taking the fight to Green Arrow, we could see an entire team of them band together, first to try and recruit him to their cause, then second to take the fight to him. That is when Solomon Grundy could be revealed as the Fist Clan's weapon. Simply put, The Outsiders War could be a spectacular season-long story.

1 A GREEN ARROW AND BLACK CANARY ROMANCE

This might be a bit controversial for some fans who would prefer to see Oliver Queen and Felicity Smoak live happily ever after. But as comic book fans know, Green Arrow and Black Canary are a famous couple, one that was brought back to prominence in DC's Rebirth. They have been through many ups and downs, but somehow they always find their way to each other.

Season five didn't see much progress in the way of love stories, but season six could be free to explore a romance between Green Arrow and a reformed Black Siren as they fight crime together, alone in Seattle. Focusing on such a classic element of the comics would ensure that season six could be the series' best yet, and ensure a seventh season for fall 2018.

What would you like to see in Arrow's sixth season? Let us know in the comments!