It's not too far off the mark to say that Arrow season 5 was something of a make or break season for The CW's flagship superhero series. Coming off a disappointing season 4 (that followed up a disappointing season 3), the story of Oliver Queen and his band of merry crime fighters was a series in decline. The show had backed itself into a corner; it had to make a statement with season 5 or risk losing even more of its audience to either the younger, more super-powered series in the universe that it birthed or any other superhero show on TV these days. And while many of Arrow's bad habits were still present and accounted for throughout his run against the ever-wily, always-ten-steps-ahead Prometheus, there's also a sense that the show was eager to, if not completely redefine itself amongst the growing throng of superhero TV programs, at least keep itself from slipping any further.

With regard to the season's overarching theme of Oliver questioning his legacy and the series coming up with the decision to depict its hero as something between serial killer and violent vigilante, at least Arrow didn't lack for giving its audience plenty to talk about. But the move to tear Ollie down to his lowest point may have also significantly reduced the series' capacity to see him rise to his former status again. Perhaps that's the point. After five seasons of back-and-forth on the to kill or not to kill debate, Arrow seems most comfortable being firmly in the moral gray area of "Well, some villains need killin' and others not so much."

That stance is put to the test, then, in the season finale 'Lian Yu', where Oliver teams up with a number of villains he hasn't killed yet – because fans really like them – in order to take down a new one who seems like he's just begging the Green Arrow to turn him into a pin cushion just to prove a point. It all adds up to a battle royale that mercifully takes the series away from a massive threat to Star City to a more personal location that will also bring the Oliver Queen flashbacks full circle. The promise is a chance for Arrow to explore new story lines in season 6, but first the show must find a satisfying conclusion for the ongoing Prometheus story line.

As far as delivering a satisfying end to Adrian Chase's season-long battle with Oliver Queen, Arrow season 5 commendably came through, delivering one the series' best finales in an episode that successfully mirrored the season 2 climax in terms of its structure, while also providing a thoughtful – if not slightly callback heavy – hour that brought a significant chapter of the Green Arrow's saga to a close. The only drawback, really, would be leaving the season on a cliffhanger that puts the lives of the both versions of Team Arrow up in the air, after Chase's dead man's switch set off a catastrophic series of explosions, turning the purgatory of Lian Yu into something more closely resembling hell.

The merits of the cliffhanger ending will be scrutinized until the series returns for season 6, when the question of who lived and who died will likely be answered. It's a great way for The CW and the series' producers to ensure a ratings boost in the fall, but it comes at the cost of this season's ending having a concrete conclusion that officially opens the door to the possibilities that lie ahead. And that's saying nothing of how the cliffhanger essentially delays the necessary emotional release that comes from a full examination of Adrian's death by his own hand and Oliver's steadfast refusal to kill his nemesis, despite William's life being on the line.

It's easy to see why the writers opted for the ending they did, though. It leaves plenty of room to shift around the Team Arrow status quo in breaking the stories for next season, and from the perspective of dedicating every minute of the finale to the task of defeating Adrian and rescuing William, not to mention doubling down on the idea of Oliver finally letting go of his past, forgiving himself for his father's suicide, and all the things that have happened since he was first marooned on Lian Yu, the writers were faced with a tough choice.

Josh Segarra and Stephen Amell in Arrow Season 5

The lack of a denouement may weaken the end of the Adrian Chase saga, but it makes the various smaller resolutions that occurred throughout the hour stronger, even if some of them were made so by default. To the writers' credit, 'Lian Yu' remained incredibly focused on giving as many characters their due as possible. Quentin Lance got in a shot at Laurel's doppelganger after the new Black Canary fought Black Siren to a near standstill, the al Ghul sisters reached an understanding in their longstanding feud, and Oliver and Felicity even got what could very well turn out to be a final kiss goodbye.

But the finale wasn't done there. First, the return of Manu Bennett brought about an older, wiser, and considerably less insane Slade Wilson, one who, despite the obvious narrative necessity of his now being a trustworthy ally, made for a moving addition to the makeshift Team Arrow that harked back to the series' second season greatness. Second, was Malcolm Merlyn's apparent sacrifice, trading his life for Thea's after she inadvertently stepped on a landmine. Sure, the lack of physical evidence that actually Malcolm died is something to consider (not to mention John Barrowman's acknowledgement that he wouldn't be a series regular next season), but it doesn't really take away from the scene's emotional weight. And yet, despite Malcolm's fatherly instinct to protect his daughter, there was probably no scene more effecting than the flashback to a recently rescued Oliver as he phoned his mother Moira. The moment featured a surprise appearance by Susanna Thompson, who, along with Stephen Amell, delivered a pair of strong performances that helped sum up the idea of Arrow bringing a massive five-year arc full circle.

All in all, Arrow season 5 aimed to reclaim its significance among the other Arrowverse titles after two disappointing seasons, while 'Lian Yu' was tasked with delivering an action-packed finale that paved the way for a (hopefully) reinvigorated season 6. The question of the cliffhanger aside, it seems as though both hit their respective targets. This was a strong season of elder Arrowverse statesman, one that gives the audience reason to anticipate the story that's yet to come.

Next: Why Supernatural Should Join The Arrowverse (& Why It Shouldn’t)

Arrow will continue with season 6 in the fall of 2017 on The CW.