'Justice League' and 'Arrow' Just Made a Funny Kind of History

Major spoilers ahead for Justice League, which is in theaters today.

With so many superheroes and supervillains appearing in both the DC Extended Universe (movies) and the "Arrowverse" of DC superhero shows on The CW, it was only a matter of time before this happened -- but last night, one character managed to become the first since Smallville -- and the only character besides Superman or Batman -- to appear in a new (non-rerun) episode of a TV show while also making an appearance in a major motion picture.

No, we aren't talking about The Flash; while TV's Grant Gustin currently plays the same role occupied by Ezra Miller on the big screen, Barry did not appear in yesterday's episode of Arrow. Green Arrow, Black Canary, and the rest of their team also did not appear in Justice League -- but there was a very special guest star who did.

After the Justice League credits roll, audiences discover that Lex Luthor has escaped from the Supermax prison seen in Batman v Superman: Dawn of Justice. On a yacht (presumably out in international waters somewhere), Luthor is joined by Slade "Deathstroke" Wilson, who hears Luthor out as he pitches an idea that will seemingly become the Injustice League.

Wilson, here, is played by Joe Manganiello, making his DCEU debut in all of Deathstroke's white-haired comics glory -- but at the same time fans were taking in Manganiello's Slade Wilson on the big screen, back at home there was a Deathstroke-centric episode of Arrow airing, with Manu Bennett reprising his fan-favorite role as the character.

After dozens of comic book movies and TV shows, it is arguably no surprise that fans could be getting two different kinds of new content from the same character on the same day, but as far as we can recall, this is the first time it has actually happened. While Superman Returns debuted, for instance, there was Smallville, but even the showrunners took great pains to point out that Smallville was a different animal: it wasn't really about Superman, who did not appear in earnest until the end of the series.

Last night's episode of Arrow not only dealt with one of Slade's sons, Joseph Wilson, but also revealed that his other son from the comics -- Grant -- was still alive. Expect more from that character down the line as he and the Arrowverse wrestle with those revelations.

At the same time, Manganiello's Deathstroke is still, at least until we hear differently, expected to be the central antagonist in Matt Reeves' upcoming film The Batman. He also has a solo film in early development.

Justice League is in theaters today.