Although DC has decided not to go the post-credit scene way, it would be fun to see them do so, the Marvel way. Without much talk, let's dive in into my idea for the post-credit scene for [Batman v Superman: Dawn of Justice](tag:711870).
After Batman, Superman and Wonder Woman have made peace during the events of the movie, the post credit scenes opens with Bruce Wayne, in his Batcave, working on his computers, looking on to some security footage of the Joker stealing a canister from a secure facility. Simultaneously, he listens to secure military lines, discussing how the Joker has gotten all the work on their 'Venom' steroids program.
Suddenly, there is a blinding flash of light, and standing there, is a guy in his mid 20s, behind Bruce.
Bruce turns and attacks the intruder, and soon realises that the guy knows everything about his combat style and has the exact same style.
After 5 seconds of punching around and martial arts, and the guy mirroring Bruce's moves.
Guy: "You told me you'd so this."
Blocking another one of Bruce's attack.
Guy: "And this."
And then Bruce finally puts him to the ground.
Guy: "I have to say, you are not half bad."
Bruce: "You let me win."
Guy: "Gotta make you listen."
Bruce: "What do you want?"
Guy: "My name is Terry McGinnis. And we need to find Hal Jordan, Barry Allen, and Billy Batson before the Parademons come in."
The screen blacks out.
P.S.: Yes, DCCU needs the Bruce-Terry dynamics.
Not only does it makes it fun, providing an opportunity for DC to create a side franchise in the future, like the Guardians of the Galaxy did for Marvel, which can remain independent, and might crossover sometimes, it also brings a fan favourite character to the big screen.
Also, DC really does time travel well.