I always said, the original SS movie should have been based arounf the 24 hours of the doomsday attack in BvS.
Amanda waller assembles a team, they go through training and then told to go back to jail and wait - this could be weeks to months - then boom, they are called in to go retrieve a subject from strykers island. They are told there is a top secret prison there and the objective is to get in, get them out and not get crushed by doomsday - they have one hour to do it when a chopper will be waiting for a one minute window.
So we see them head their, as in the back ground, foreground, we see the events of BvS play out, similar to the start of that movie with zod.
We have a scene where deadshot see's batman, does he go for him, or stick to the plan etc. The nuke goes off in the sky, all these cool nods to bvs. We see a blast from WW in the horizon, we see the bat wing fly by.. at times they just stop and think 'what is going on'.
They finally get there, the prison is on lock down, but it's a mess inside - it's gruesome, there are some cool villains from superman's rogue gallery, a nod to what he has been doing for the past 18 months - then they find who they are looking for - it's Amanda Waller and a sedated .
They get out, obviously annoyed, they go off, as they look back and see the city quiet... is doomsday dead??
Credits roll
Post credit scene.. Waller is talking to Rick, she introduces him to Bronze Tiger and throws him a file about 'onslaught'.