One of the many fan-favorite characters audiences became familiar with from the CW’s Arrowverse is John Diggle, played by David Ramsey. Even though he was created for TV rather than the comic books, he’s been a main character since Arrow began, and has had major appearances in every other show in the shared TV universe. He’s served as Oliver Queen’s security guard and bestfriend, an agent of A.R.G.U.S., and a crime-fighting vigilante under the alias of Spartan.
During Arrow’s finale, a box containing a mysterious green light crash lands on Earth and is quickly discovered by Diggle. This is a clear hint at him becoming a Green Lantern and an answer to years of fans speculating that he was secretly John Stewart all along and begging for that to become a reality. He then receives a new story arc in which he travels to the various remaining Arrowverse series to learn more about this strange artifact. In a season 8 episode of The Flash, though, he finally reopens the box and learns the information he’s been searching for and rejects the powers that reside within, turning down what is almost definitely the role of Green Lantern.
Not using John Diggle as the full-fledged Green Lantern was a massively missed opportunity. Green Lantern is one of DC’s biggest superheroes. Giving him his own live action TV series would be a quick win for the network. Plus, a character who fans have grown to love becoming the iconic hero would be icing on the cake.
There were a handful of hints throughout the series that ended up going nowhere. Another Green Lantern, Hal Jordan, is teased during season 1 of The Flash when we see a man in a bar wearing a bomber jacket with “Jordan” printed on it, but his face is never shown. During the “Elseworlds” crossover event, the Flash of Earth-90 says to Diggle that he’s not “wearing his ring.”
The biggest sign that John Diggle is in fact meant to be Green Lantern came in a later episode of Arrow. We’re introduced to Diggle’s stepfather, played by legendary Ghostbusters actor Ernie Hudson. Hudson’s character is named General Roy Stewart. John Diggle’s stepfather’s surname is Stewart, giving cause for him to take on the name of John Stewart. Why go through all the trouble to confirm what fans have wanted to then not do anything with it?
On top of fans begging for it, the folks at the CW dropping hints, and even an in-story reason he is actually John Stewart being created, it also fits the character perfectly. Both John Diggle and John Stewart share very similar personalities and were both former members of the US military. If anything, perhaps John Diggle should have been John Stewart from the start.
Regardless, they set John Diggle up to be the Green Lantern for quite a while, and then didn’t really do anything with the idea. It all feels pointless to have done anything with it now. Imagine how cool it would have been to see David Ramsey suited up as the Green Lantern taking on the likes of Larfleeze and Atrocitus.