Spoilers for Justice League ahead. Justice League is in many ways the unofficial sequel to Batman v Superman, so it's surprising that BvS's main villain, Lex Luthor, is barely mentioned in the new film. That is, until the second Justice League post credits scene. As made clear in the scene, the Justice League is about to face a new enemy much closer to home in the form of the evil genius. But, believe it or not, Lex isn't even the biggest DC bomb in the scene. The second Justice League post credits scene introduces Deathstroke to the DC Extended Universe (DCEU), and gives a clue as to what's next for this new, dangerous villain.
The second Justice League post-credits scene actually has two parts. The first begins at Arkham Asylum, the prison/asylum Lex Luthor was headed to at the end of B v S. Only, this time, the bald man in the straight jacket standing in Luthor's cell isn't Lex. He's just a lookalike. The scene then cuts to a mysterious, sword-wielding figure. Dressed in full black and orange armor — face obstructing helmet included — the man approaches an enormous yacht, supposedly floating off the shores of a country without extradition, where he meets the real Lex. The man takes off his helmet to reveal Deathstroke as Lex teases, "Shouldn't we have a league of our own?"
Before we unpack that statement from Lex, let's take a look at Deathstroke, as played here by a blonde (or is that white hair?) Joe Manganiello. The new villain is pretty well known in the DC Universe — fans of The CW's Arrow are already quite familiar with the villain. Also known as Slade Wilson, Deathstroke is, essentially, a genetically enhanced super solder (think Captain America, but evil and good with a sword). After leaving the army, he became a mercenary and quickly worked his way up in the criminal world (in Arrow, he's a killer with a vendetta against the Green Arrow). He's described on the DC Comics website as "the world's greatest assassin and one of the most feared people on the planet."
It's unclear how this new villain will fit in with the DCEU. When it was announced in 2016 that Manganiello would be joining the franchise as Deathstroke, it was rumored that he would be the main villain in a stand alone Batman movie. Now that said Batman movie is currently up in the air, there seems to be no end of possibilities when it comes to the character's role in movies to come. However, his alliance with Lex Luthor is a major clue, hinting that whatever comes next might have something to do with the Injustice League.
Created by Lex Luthor in direct opposition to the Justice League, the Injustice League is straight from the comics, and counts Deathstroke as one of its members. Other villains in the group, according to Movie Pilot, include the Joker, Poison Ivy, Black Manta, and many more. If Lex is, indeed, putting together the Injustice League, then fans should get ready for an onslaught of DC villains heading to the big screen. It should be pointed out, however, that this could just be a wink to comic fans (or a plug for the feminist sports classic A League of Their Own). Perhaps Lex really is only reaching out to Deathstroke, and the DCEU has no intention of bringing together the Injustice League. It's certainly possible, but unlikely, considering Justice League star Ezra Miller's already enthusiastic talk about the coming of the Injustice League.
Miller, who plays Barry Allen, aka the Flash, told fans in an interview that he hopes the Injustice League is the villain of a potential Justice League sequel. "We don't really know for sure, and we're usually the last people to find out," he teased the Toronto Sun when asked about future villains. "Each of the heroes in this movie has specific nemeses, and I think seeing some incarnation of the Injustice League (which includes Lex Luthor, Joker, Deathstroke, and more) would be something that DC fans would be pretty stoked about."
A Justice League vs. Injustice League showdown would certainly make for a can't miss movie event. Maybe Justice League really is the beginning of a beautiful franchise.