The Arrowverse is at a pivotal point. First, Lian Yu exploded with most of the Arrow cast on the island, which leaves their fates unknown. Then, on The Flash, Barry left his friends and loved ones behind in a last-minute decision to live in the Speed Force. Kara just said a tearful good-bye to Mon-El, who got sucked into a wormhole on Supergirl. Finally, Eobard Thawne was killed, for good, on Legends of Tomorrow, which leaves an opening for next season's big bad. The Arrowverse shows could go in just about any direction, which means it's time to examine the current cast members.

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If there's one thing comic book fans know, it's that when a series gets tired, a new superhero can give it new life. Arrow, now in its sixth year, is showing signs of wearing down, and handing off their masks to new members of the team would be a great way to re-energize the show. Likewise, the novelty of The Flash is wearing off, and the writers are having to dig deep to keep things interesting. New characters would bring a lot of variables to the writers' table. Across the board, the Arrowverse would benefit from some casting shake-ups. CBR has 15 ideas of who should be replaced.

15 HARLEY QUINN

Harley Quinn Arrow

Even Harley Quinn, who enjoys the occasional torture session, would have been miffed at Arrow's character tease in Season 2. In the "Suicide Squad" episode, fans caught a glimpse of a woman in blonde pigtails wearing an A.R.G.U.S. uniform. That was all the audience saw of Harley Quinn, but their excitement over the possibility of Harley wreaking havoc in Star City ramped up quickly.

Their hopes were quickly dashed, however, when rumors popped up that Warner Bros. had axed Harley Quinn from Arrow because she would play an important role in Suicide Squad. Even executive producer Marc Guggenheim said at the time that she was only meant to be an Easter Egg, because Tara Strong, who voiced the role in Batman: Arkham City, dubbed lines for actress Cassidy Darling. If the Flash can appear in movies and on TV, so can Harley. It's time to bring her back.

14 MARTIN STEIN

Martin Stein Jason Rusch

Dr. Martin Stein has been part of the Arrowverse since the first season of The Flash. At first, he was only a curmudgeonly mentor. He became Ronnie Raymond's other half of Firestorm, then Jefferson Jackson's partner on Legends of Tomorrow. While the two of them seem to get along well, they have very different personalities and backgrounds, which makes it difficult for them to become true friends. Plus, Dr. Stein's lectures are becoming quite tedious.

A new Firestorm combination would inject some life into an increasingly boring partnership. Jason Rusch, who became Firestorm in the comics, would be an interesting addition to the Legends. He was already established on The Flash as someone who worked with Dr. Stein on the F.I.R.E.S.T.O.R.M. project. Jackson and Rusch would have much more in common, and their partnership could prove to be action-packed.

13 BLACK CANARY

Black Canary Black Siren

Killing Laurel Lance in the fourth season of Arrow was a disastrous move. The Black Canary was a valuable member of Team Arrow, and Laurel's chemistry with Oliver wonderfully portrayed their history together. Although Dinah Drake became the new Black Canary, her role on the team hasn't been as important or as powerful as Laurel's was. Plus, she has almost no relationship with any of the existing team members.

Bringing back actress Katie Cassidy full-time would help raise Arrow out of the rut it has fallen into. Dinah could disappear and the show wouldn't experience a single hiccup. It would be much more interesting to watch the villain Black Siren turn into a hero, with Oliver's help. She would also make a wonderful third party in a love triangle, along with Oliver and Felicity.

12 GUARDIAN

Guardian Maggie Sawyer Supergirl

James Olsen has had little to do on Supergirl since Kara broke up with him. Cat Grant handed him the reins to CatCo Worldwide Media, but that took him out of Supergirl's orbit, and left him out of most of the action. He suited-up as the Guardian, but his night-time escapades still didn't pack the same punch that Supergirl's high-flying fights did. In other words, James Olsen got boring.

Why not keep James in the office and cast someone new in the role of Guardian? Jim Harper was the Guardian in DC Comics, but Supergirl already has a kick-ass crime-fighter on its roster who could step into the Guardian's boots: Maggie Sawyer. The relationship between Maggie and Alex is one of the meatiest and most entertaining parts of the show. Why not give Maggie even more to do? She would have an even stronger role at the D.E.O. and on the show.

11 THE ATOM

Atom Atomica Legends of Tomorrow

Just as Dr. Stein's lectures are growing tedious, Ray Palmer's nerdy tendencies and lack of personality are becoming nap-inducing. Ray hasn't grown as a character since he was introduced on Arrow. After two seasons on Legends of Tomorrow, he's just as bad at fighting and just as awkward socially as he ever was.

Rhonda Paneda, as Atomica, would be a terrific swap. Ray is already terrible in combat, so he could easily be killed. Because Rhonda was an evil member of the Crime Syndicate, she could become either an enemy of the Legends, or someone the Legends decide to rehabilitate, much like they did with Mick Rory. Either way, her story would be much more entertaining than Ray's. Wait, does he even have a story anymore? Plus, Legends of Tomorrow could use another woman in their cast.

10 KILLER FROST

Caitlin Snow Louise Lincoln

As soon as The Flash cast Caitlin Snow, fans waited breathlessly for the day Killer Frost would make her entrance. Season 2 gave us a tease of Killer Frost, but she didn't make a complete transformation until Season 3. However, she never became a vicious killer, and she didn't have any interactions with Firestorm, who is her lover and nemesis in the comics.

Sadly, by last season's finale, Killer Frost wasn't having any fun, and left to go find herself. This is the perfect time for Dr. Louise Lincoln to assume the chilly title. Lincoln has a storied past. In comics, she tangled with Firestorm and Green Arrow, which would make for a great crossover arc. While Caitlin feels conflicted about her powers, Louise could embrace them and become a much better villain.

9 ARTEMIS

Artemis Arrow

Evelyn Sharp was a new member of Team Arrow. Although her real name has no basis in DC's source material, her alias, Artemis, does. Artemis Crock becomes Tigress in DC comics. However, she plays a larger role as Artemis in Young Justice. Young Justice remains the best cartoon depiction of Teen Titans, and Artemis was a fan-favorite character. Just like Evelyn, Artemis had a complicated past and was sometimes conflicted about her role.

Although Evelyn Sharp was pivotal in Prometheus's plans, as a character, she had little to do and didn't spend much time on Team Arrow before betraying them. She could conveniently end up dying on Lian Yu, which would leave an opening for another Artemis to step in. An exciting up-and-coming actress could be cast in the role, which could even morph into Tigress in the future.

8 HUNTRESS

Huntress Arrow

One of the most promising stories on Arrow happened in the first season, then was completely forgotten. Helena Bertinelli was a disheartened daughter of a mob boss. When she vowed revenge on her father, and all of his associates, she became the Huntress. She and Oliver Queen had fantastic chemistry, with a romance reminiscent of Batman and Catwoman's tumultuous relationship.

Although having Bertinelli back as Huntress would be wonderful, she's in prison. Now is the perfect time for a new Huntress to heed the call. Helena Wayne is another Huntress who could give Team Arrow a run for their money. She even has an interesting past -- as Bruce Wayne and Selina Kyle's daughter -- to give Arrow more variables to play with, which it sorely needs.

7 RIP HUNTER

Rip Hunter Booster Gold

Rip Hunter has been the weakest link in Legends of Tomorrow since its debut. He spends most of his time brooding and being the proverbial wet blanket. Now that Sara Lance is captain of the Waverider, he has an even smaller, and less important role on their team. Plus, his continual negativity is a drag on the series.

Enter Booster Gold, the superhero from the future. Booster Gold worked alongside Rip Hunter in Time Masters: Vanishing Point, by Dan Jurgens, so he could take over Rip's duties to the timeline. Along with relieving Rip of his job, he could relieve the drudgery Rip leaves in his wake. Booster is a high-spirited time traveler, full of mischief and mayhem. His self-aggrandizing would be a welcome change from Rip's dour personality.

6 HAWKGIRL

Hawkgirl Legends of Tomorrow

Oh, Hawkgirl, we hardly knew ya! The CW spent months getting fans hyped for Hawkgirl. She was introduced as an Easter Egg on The Flash, but savvy fans spotted her right off. She was part of a big promotional campaign that covered Hawkgirl's appearances on The Flash, then Arrow, and finally on Legends of Tomorrow, where she became a regular cast member.

However, her role was squandered. Rather than spend the first season battling like the warrior she is, she spent it whining about whether she should love Ray or Carter. She was such a wishy-washy character that her exit was a relief. However, having a flying superhero with warrior skills would really come in handy for the Legends. They should resurrect the true Hawkgirl, Shayera Hol, and let her become the badass she should have been.

5 HAWKMAN

Hawkman Legends of Tomorrow

If Hawkgirl's role on Legends of Tomorrow was squandered, Hawkman's role was cut short. Although Kendra had too little to do as Hawkgirl, she and Carter shared a wonderful history that came through their chemistry together. But Hawkman was killed off far too soon.

Rather than bring back Carter as Hawkman, Legends of Tomorrow could cast Katar Hol as Hawkman on the team. Exploring his and Shayera's origins on Thanagar would add another dimension, literally, to the show. The Legends have explored a lot about time travel, but nothing about other dimensions or planets. With Eobard Thawne's story all wrapped up, the time is ripe to introduce a whole new level of storytelling. A new Hawkman and Hawkgirl would lift up a show that has trouble getting off the ground.

4 SUPERGIRL

Supergirl Cir-El

Supergirl is a powerful role model for young girls and women, one of the few female superheroes being depicted onscreen anywhere. While the existence of her show is groundbreaking, she remains an ideal that few women can relate to. She is sweet and innocent, blonde and blue-eyed. She's very lovable, but a little too perfect.

Cir-El, on the other hand, is a flawed, confused girl with super-powers who is very relatable. She is another female who took the name Supergirl. While she thought she was the daughter of Superman and Lois Lane, she turned out to be the product of one of Brainiac's schemes. After watching Kara moon over Mon-El last season, watching a girl struggle with her evil tendencies and her anger would be a refreshing change, even if it were just for one season.

3 FLASH

Barry Allen Sela Allen

The Flash is arguably the CW's best superhero TV show. The Season 3 finale, however, left a lot of the audience scratching their heads. Flash defeated Savitar, but with only minutes left in the episode, the Speed Force started tearing Central City apart, and Barry decided to sacrifice himself to save everyone.

The end was confusing, but clearly Barry was looking forward to a break, even if that meant being trapped inside the worst moment of his life for eternity. Now is the time for a new Flash to step forward, but not Wally West. He looked like he needed a break too. Sela Allen is a Flash from the future, who is the embodiment of the Speed Force. The Speed Force has already meddled in Central City. She could be a by-product of all the time travel and Speed Force shenanigans. Also, the CW could use another female lead.

2 SPEEDY

Thea Queen Mia Dearden

Thea Queen became the red-hooded Speedy in Season 3. While she was an amazing asset to Team Arrow, her constant struggle with her inner demons held her back. She couldn't make up her mind who she was, a ruthless killer or a noble defender, which was frustrating to watch. She had less and less to do with Team Arrow, and was M.I.A. for most of Season 5.

Arrow would do well to let Thea die on Lian Yu and introduce Mia Dearden as Speedy. Her appearance would be organic because her origin story includes being rescued from a child prostitution ring by Green Arrow. Arrow needs fresh blood and fresh characters, and Mia would bring both. Her fierceness as a fighter would be a better fit than Thea's impotent attempts.

1 GREEN ARROW

Oliver Queen Connor Hawke

The biggest reason Arrow is becoming tired is because Oliver's story is played out. The Lian Yu timeline came full circle, with all the flashbacks filling in the complete story as to how Oliver became the Green Arrow. He's loved and lost just about every lady on the show, so even his romances feel tired. Stephen Amell has been wonderful as Oliver Queen, but now that his acting career is hotter than ever, he is no doubt considering his next move.

The perfect replacement for Oliver Queen was already introduced in an episode of Legends of Tomorrow. When the Legends visit Star City in 2046, they find the Green Arrow battling a band of criminals. However, the man under the hood is John Diggle's son, who calls himself Connor. Although he's called Connor Hawke in the comics, this Connor could take the Arrow series in a whole new, and exciting, direction.

Who do you think needs to leave the Arrowverse? Tell us in the comments!