Multiple new threats emerged in Titans season 2, but the final episode made the mistake of concluding those arcs in the wrong order. Starring Brenton Thwaites as Dick Grayson, Titans season 1 emerged as a bonafide hit for both DC Universe. Rapidly renewed, Titans season 2 saw the return of Anna Diop as Starfire, Teagan Croft as Raven, and Ryan Potter as Beast Boy. They were joined by Conor Leslie as Wonder Girl, Alan Ritchson as Hawk, and Minka Kelly as Dove - each of which were retconned to have been part of the original team of Titans. Curran Walters reprised his role as Jason Todd. Titans season 2 also saw the introduction of such heroic newcomers as Rose Wilson and Superboy.
With the new heroes, however, came a host of new villains. Titans season 2 saw the introduction of Connor's nefarious creators at Cadmus Labs. After rounding off the lingering threads from the Titans season 1 finale, Esai Morales also made his debut as Deathstroke. As part of season 2's retcon, flashbacks revealed that the Titans and Deathstroke had a storied history filled with tragedy. Each of the new threads culminated in the Titans season 2 finale - with the team facing down Deathstroke before then rescuing Gar and Connor from Cadmus' sinister control.
In reflection, however, the Titans really should have approached their enemies the other way around. Deathstroke, after all, was established as the primary antagonist in the Titans season 2 premiere. Following that, a large swath of the story was dedicated to establishing the motives for Deathstroke's vendetta. Equally, it also shed light on the means through which he sought to destroy Dick Grayson and his team. Throughout Titans season 2, Deathstroke served as the face of the Titans' demons - the anguish of which Dick Grayson had to face, atone, and overcome in order to finally complete his evolution into Nightwing. Mercy Graves and Cadmus, meanwhile, were introduced relatively late in the season. And while Titans tried to add shades to Mercy Graves' character, this largely fell flat and lacked the time and definition that made Deathstroke so compelling. As such, seemingly killing off Deathstroke in the first quarter of the Titans season 2 finale was a mistake.
Deathstroke - and Titans itself - would have been much better served had they treated him as the final boss. The crux of Deathstroke's endeavor was to keep the Titans apart and resign Dick Grayson to a lonely life. To that end, Deathstroke repeatedly stated that he would kill them all if they ever reunited. By dealing with Cadmus first, the stage would have been set for a grand reunion as the Titans found their way back to each other and rescued two of their own. Reintroducing Deathstroke here, amid public adulation, would've had him living up to his mantra. Plus, it would have granted the Titans season 2 finale the kind of impact and tension it lacked.
Utilizing Deathstroke as the true Big Bad of Titans season 2 could have also elevated Donna Troy's lackluster (and dumb) death. Everything with Slade Wilson began with his murder of Aqualad. As such, making Deathstroke the one to pull the trigger on Donna would have had a poetic symmetry - especially if she, too, sacrificed herself. Equally, the moment would no doubt have been a powerful one when the Titans opted to band together in the wake of tragedy rather than break under its weight. And instead of simply reducing Deathstroke to being Dick Grayson's fight, it would have provided the perfect opportunity to have the entire team finally working in unison to bring down their longtime nemesis.
All fans can do, however, is lament what could have been. As well as hope that, with Titans season 3 confirmed for 2020, the writers learn from their missteps. In a tease similar to the one afforded Deathstroke, it's implied that Blackfire will be the team's next main antagonist. With an equal opportunity for a rich and personal history with some of the characters (namely her sister, Starfire), it would be a shame if they were to end up similarly sidelined when Titans eventually does return.