I've always said -- and this is quoting a post of mine from
January 2014:
"Would love to see the film end with a cliffhanger of Superman being killed...
And the Justice League is formed by Batman as an attempt to re-create a Superman in the aggregate. Wonder Woman-Strength, Flash - Speed, Green Lantern - Flight, etc...
Culminating with Superman returning in the end of the second act of Justice League.
Killing Superman in a way that makes people BELIEVE he is dead will at the very least make people feel that the threat the Justice League faces is credible. Otherwise, why need a Justice League? Superman could just take the threat out...."
In
Man Of Steel, Superman takes down an army of Supermans, essentially. He takes down an army of rogue Kryptonians. If he can do that on his own, what threat would require him to need partners, let alone 6 other super-powered (well, 5) beings? He's SUPERMAN.
So, if you show that he can be killed. Or you establish a threat that he alone cannot handle, then you realistically show that there is a need for there to BE a Justice League team.
Would love to see
Justice League: Part 1 begin with Bruce and Diana recruiting the team and the world under some sort of threat. When the team (without Superman) is still overwhelmed by this threat, you bring Superman back in the third act to complete the League and show his importance to the DC Universe.
Hoping my prediction/hope from a few years ago has panned out to be true.
-R