Arrow has often flirted with characters in the Justice League (of which Green Arrow is referred to as the “8th man” of the team) by using Easter Eggs and one-liners to show that the series isn’t without some meta moments.
The biggest one, and arguably most frequent one, is the frequent references to Green Lantern. In both Flash and Arrow, which share the same universe, references to Hal Jordan, his dad, and his hometown of Coast City have been shown. Now though, in Season 5, it appears that the biggest tease of Green Lantern is coming in the form of his sister-in-law.
As reported by TV Line, Carly Pope has been cast in Arrow as Susan Williams. A reporter who will apparently be trying to be doing a big story about Oliver Queen. This makes sense as at the end of Seasons 5 Queen became the mayor of Star City.
The reference to Green Lantern is in the character itself, as Susan is married in the comics to Hal’s younger brother Jim, and does know Hal’s “secret” of being Green Lantern. Now, as Jordan is likely going to be in the DCEU, it’s unlikely some references or name dropping will occur, but we have been surprised before.
Susan Williams will arrive in the third episode of Season 05.