EW
With [
Superman] out of the picture, the League cant rely on his invulnerability either.
And a part of the reason they team up is to find a way to bring Superman back much like the goal of Star Wars: The Force Awakens was to rediscover Luke Skywalker.
Exactly how theyll bring Superman back is still unclear. The rocks rising off the coffin was meant to suggest a lifeforce is still present, but its not simply a matter of sunlight rejuvenating him (as it does in an earlier sequence in BvS when Superman is wounded in a nuclear explosion in outer space.)
He comes very close to death in space and the reason why we did that is because I wanted to show and keep the idea in the viewers mind that he can come pretty close to death and the sun can revive him, or he can be revived, Snyder says, although after Doomsday, the Justice League is going to have to take more drastic measures of resuscitation. I think something more is gonna need to be done.