The first three series of Phase 4 all directly pick up from the events of Endgame, and numerous entries in Phase 4 and 5 continue to focus on characters dealing with the aftermath of the film. The leader of the Avengers, World War II veteran and former fugitive, he was enhanced to the peak of human physicality by an experimental serum and frozen in suspended animation before waking up in the modern world. He's just lashing out at everything Batman cares about in both his civilian and superhero identities as thoroughly as possible while still having a jester motif to part of his crime (in the case of the plague). In India, the film sold one million tickets in just one day for the English, Hindi, Tamil, and Telugu language screenings; 18 tickets were sold every second.

The second trailer for the film, along with the theatrical release poster, was released on March 14, 2019. Hate Plague: The Plague that Joker has released apparently makes people target their friends, according to Jim Gordon. The film, along with Infinity War, were shot using ARRI Alexa IMAX 2D cameras, thus marking the first time that a Hollywood feature film was shot entirely with IMAX digital cameras. O. Scott gave the film a positive though guarded review, stating, " Endgame is a monument to adequacy, a fitting capstone to an enterprise that figured out how to be good enough for enough people enough of the time.The featurette included a tribute to the late Stan Lee, a deleted scene featuring The Hulk, and the opening scene from Spider-Man: Far From Home.

In June, Feige announced that Avengers: Endgame would be re-released in theaters with seven minutes of new post-credits footage, including a Stan Lee tribute, an unfinished deleted scene, and the opening scene of Far From Home. The Russos started working with Silvestri on the Endgame score in early November 2018, [111] and it was completed in late March 2019.Batman eventually recovers from his paralysis to find that the Joker has released an incurable airborne pathogen throughout Gotham, transmitted by laughter, that makes the victim look like the Joker, and turns feelings of love into violent hatred, triggering mass chaos. Resigned to their fate, Batman reveals that the Joker has failed, as Batman gave his allies small doses of Dionesium, to protect them from Joker's poison, while he has recovered a larger amount of the Dionesium for Julia to cure the citywide plague.