Okay, here's how the film in my head would start...
Spoiler!!! Click to Read!:
It's been somewhere between six months to a year since the end of the first film, and perhaps a little longer than that since the great battle against Zod- it depends on how long it was between the fight against Zod and Clark getting his job at the newspaper. But, unlike the barren hellscape that much of it was left as after the Kryptonian invasion, we see a helicopter shot of the part of the city being reborn: Skyscrapers are being built...
We then cut to seeing some of those buildings being built: supports being laid for new buildings, windows being placed on buildings that had only been superficially damaged... and as we see this montage- think of one of those “get our people back to work” montages that politicians of both parties do- we hear a voice, a powerful voice with much purpose in it... the voice of LEX LUTHOR!
LEX LUTHOR (v.o.)
In Greek, Metropolis means “Mother City”. And, for us, Metropolis is our Mother City. For many of us, we are born to it, for some of us, it is our adopted mother. But, no matter how we came to call this city our mother, it is ours. Which is why, when the aliens attacked, when our buildings fells and our fellow citizens were lost, it felt like we-
Cut to an audience, standing, listening to Luthor. We pan over some of the reporters tapping at their keyboards (tweeting and writing), most notably LOIS LANE but also a small you-wouldn't-know-it-unless-you-looked-in-the-credits appearance by more minor reporter characters like the Daily Star's TOBY RAYNES, the Gotham Gazette's VICKI VALE and ED RAYMOND of the New York News Express. We also cut to Police Officers, like MAGGIE SAWYER and DAN TURPIN, standing watch while also paying tribute to the dead, and also ordinary citizens... watching and listening....
LEX (v.o. continued)
-had seen our own mother attacked. Our shining star, our Metropolis, our mother, with it's heart ripped out. Lesser cities... lesser people... would have given up to despair, but this is Metropolis. We will lift back up our mother city-
CUT TO Lex Luthor himself speaking. He looks every bit the businessman-style of Lex, and his head is bald as a cue-ball. He stands at a podium upon a stage, with a red ribbon behind him and dignitaries like the Mayor and such behind. As he speaks, his hands speak too- emphasizing every piece of rhetoric he says. It's a technique used by great speakers of every stripe and ideology throughout history, and Lex is a master of it.
-we will build the finest example of what humanity can accomplish, while reaching for the sky! And, LexCorp will aid you, the people of Metropolis, in seeing that our city is reborn, as a city that lives up to its past and define its future!
The crowd applauds while Lex soaks it in. Cut briefly to the Daily Planet office, where CLARK KENT is watching the speech on TV while working on a story. Back with Luthor, he motions for them to stop, and he resumes speaking...
Thank you, but, of course, LexCorp is but one corporate citizen in the Metropolis family, and this would not be possible without...
BAM! The sound of a gunshot! A few bullets comes screaming at the stage, and although all of them miss Luthor, chaos breaks out. Luthor quickly points to where he thinks the shots came from before a bodyguard knocks him to the ground.
CUT TO Lois looking upwards, seeing a figure moving away, carrying some sort of weapon while the Metropolis Police begin to fire shots at the figure. But while everyone else runs away... she runs towards it...
CUT TO the assassin running through the building he had used as his sniper's perch. He weaves his way down various stairs and then out of the door, where he's met by a SECURITY GUARD.
The assassin (who we later find out is named JOHN CORBEN) pulls out a pistol and shoots the guard and then runs towards a car nearby, soon speeding off.
We cut quickly to the Daily Planet, where STEVE LOMBARD is coming to Clark Kent's desk
Hey, Kent, I got extra tickets for the Meteors game to-
Lombard notices that Kent isn't there.
I cut away before the action sequence where Superman chases Corben and it ends with Corben getting into a horrific car crash rather than be captured by Superman. Why? Partly because of time, and partly because action sequences are a ***** to write. But needless to say, I'm sure it'd be a fun way to open the movie as Superman tried to stop Corben while also trying to contain the chaos he would be causing as a way to slow Superman down.
(Oh, and I took some lines of Lex's speech from the excellent miniseries Lex Luthor: Man of Steel, although the context is changed a bit.)
Marvel. DC. Indies. Who cares? Can't we all get along?