WARNING: The following contains major spoilers for the DC Animated Universe's Reign of the Supermen, now streaming on DC Universe and available for digital download.

When the post-credits scene for 2013's Justice League: The Flashpoint Paradox kicked off the DC Animated Universe, few expected it to blossom into a continuity stitching together so many comic-inspired events. Since Justice League: War first assembled its heroes to confront Darkseid's invasion, we've got 12 movies, with Reign of the Supermen being the latest.

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Following up last year's Death of Superman, the film focuses on four Supermen battling to replace the Man of Steel, adapting the eponymous '90s DC Comics storyline that brought Kal-El of Krypton back to life. However, after the dust settles and Clark Kent dons the cape again, we get a post-credits scene that redefines the DCAU's Justice League.

After Darkseid failed at using Hank Henshaw (the Cyborg Superman) to turn Earth into New Apoklips, the Justice League decides the time has come to take drastic action. They came close to losing their home, after all, as Hank marooned them at the edge of the galaxy using a boom tube, and it's only when Lex hacked his Apokoliptan technology that the Leaguers were able to return home and help repel the Parademon invasion. The post-credits scene now paints a more aggressive League, angry that Darkseid had to gall to try to subjugate Earth once more.

"Henshaw may be gone, but still, this has been the boldest move we've seen from Apokoliops yet!" Says an angry Wonder Woman. Even Batman admits they "can't play defense forever." With everyone's support, Superman makes it a unanimous decision, emphasizing they need to take the fight to Apokolips' doorstep, once and for all. Hawkman, Martian Manhunter, Flash, Green Lantern and Cyborg are ready for action, but as this decision is made, the newest member of the League arrives: Lex Luthor.

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The doors to the Watchtower's main chambers open and Lex walks out in his iconic purple-and-green war suit, taunting, "Excellent! Count me in... team!" But as snarky as he is, it seems like a natural fit given Lex helped stop Darkseid's invasion by shutting down his boom tubes, as well as the tech Hank's soldiers were using. Seeing as Lex brought the League back too, it does seem that he's earned his spot and possibly a shot at redemption. Still, one has to wonder who invited him, or if he stormed the party.

Even Green Lantern (Hal Jordan) comically asks, "Okay, who left the front door open?" It could be that Batman invited Lex, as he knows how big a genius Lex is with Apokolips' tech. It'll be interesting seeing how Lex integrates with the team moving forward, especially after combining his DNA with Superman's to create Superboy, something that's sure to extend their feud.

Seeing as the DCAU is heavily influenced by the New 52, this development throws back to 2014 when Lex actually joined the League to help them prepare for threats from the Crime Syndicate's universe. His initial lobby to become a Leaguer was rejected, but eventually, as he was going to embark on his crusade with or without them, they allowed him to join knowing he'd be resourceful in gathering the right intel.

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Also, Batman felt they could keep a close eye on LexCorp this way. Either way, whatever the DCAU has in store next, we expect it to be a wild adventure with the assault on Apokolips impending and the League gaining a member they're certain to never trust.

Directed by Sam Liu, Reign of the Supermen stars Cameron Monaghan, Jerry O’Connell, Cress Williams, Patrick Fabian, Rebecca Romijn, Nathan Fillion, Rainn Wilson, Toks Olagundoye and Nyambi Nyambi. The film will be available on Digital HD on Jan. 15 with a Blu-ray release on Jan. 29.