Diggle’s day is done. Oliver Queen’s partner and confidant on Arrow has had a solid run throughout the series’ first two and a half seasons, but its time for the character to take a rest—indefinitely.
Now, before the torches and pitchforks come out, listen for a minute. It’s true that Diggle has been one of Arrow’s stronger characters. As Oliver Queen has evolved from the Vigilante, to the Hood, and now to the Arrow, Diggle has been there as his rock and morale compass. But the problem now, is that Diggle has carried Oliver past a point where he can realistically still aide him. Oliver Queen is the Arrow now, a full-blown superhero who teams up with The Fastest Man Alive and fights immortal assassin leaders. As Arrow’s adventures develop their taste for Justice League-level conflicts, Diggle will become increasingly outclassed and unable to relate.
That’s why the show needs to do away with him now, before the character becomes completely irrelevant. The signs are already there. While Arrow used to only have Diggle, he now has Felicity Smoak and Arsenal too. Black Canary is just around the corner, and it’s only a matter of time before Thea Queen dons the Speedy mantle and Ted Grant becomes a true Wild Cat. Add in fact that Ray Palmer is trying out his superhero duds and Barry Allen is just a crossover away, and Arrow has a quasi-Justice League waiting in the wings. That makes for a pretty full party, and one that Diggle may not be able to fit into. If Arrow does continue its evolution into a full-blown superhero show, this problem is only going to develop. As the plots and missions become more fantastical and colorful, Diggle’s presence will make less sense. Yes, Arrow and his crew (minus Roy Harper) are all self-made mortal heroes too, but they're spending all day, every day, in these extremely hostile enviornments. They're building and preparing themselves for the absolute worst, like Vertigo, Cupid, and Ra's al Ghul. Diggle, despite his optimal military training, simply isn't grooming himself for the same levels of conflict. While he can undoubtedly hold his own right now, those days are becoming increasingly scarce. It’s of like bringing a knife to a gun fight, only to discover that the gun fight was actually a bazooka fight. This doesn't make Diggle any less of hero. He's just as tough and selfless as the rest of Team Arrow, but he no longer fits into the crime fighting equation that Oliver is constantly developing.
And this idea didn't just appear out of thin air. Arrow laid the seeds for this this season. Now that Arrow has Arsenal to back him up, Diggle’s role in field operations have taken a dramatic dip. He's spent an increasing amount of time hanging around in the Arrow Cave, offering little more than piece or two of sage wisdom to Oliver. It feels a bit like a demotion. And as a character with his own complex back story and nuances, Diggle deserves to be in the driver’s seat, or none at all.
So, Arrow has two solutions to this problem. It can either kill Diggle, or let him ride off into the sunset. The first choice is a solid possibility, given Arrow’s raised stakes. In fact, Season Three seems like the perfect place for Diggle to die. With Arrow on the ropes, and Ra’s al Ghul’s attacking Starling City, Diggle could step up and have his big moment. By sacrificing himself for the city, Diggle would have a hero’s death that’s worthy of the character. Plus, his demise would serve as a constant reminder to Oliver and company that their mission is becoming increasingly dangerous. Arrow isn’t about cops and robbers with masks anymore, and Diggle would be the perfect monument to that idea.
The second choice, retirement, is equally feasible, if not as dramatically appealing. Now that Diggle’s a family man, he has the perfect out. With a wife and infant to support, he might realize that he has to consider those depending on him. With Starling City's escalation of super-crimes, Diggle could decide that the risks and their consequences just don’t add up anymore. With the direction the character and show are heading, no one on Team Arrow could begrudge Diggle for wanting to focus his attention on those who truly need him. We’re sure ARGUS could give the character a comfy desk job, which could keep alive and active in the Arrow universe. As an occasional presence who could visit Team Arrow every once in a while, Diggle and his fans could eat their cake and have it too.
But no matter how you slice it, Diggle has to go. The show has outgrown him, and that’s not necessarily thing. Diggle’s exit would mark a tangible end in a chapter of Arrow’s career, showing a clear divide between his time as a vigilante, and as superhero.