Fan Casting

Darkseid's appearance in Justice League was more or less a tease of what was to come in Justice League 2 for when he became the primary antagonist. He never got the chance to defeat the Justice League and Steppenwolf failed in his mission to secure Earth for his arrival, one that included the anti-life equation that would have been used to control all life on Earth. With Steppenwolf dead and Darkseid still planning to storm Earth (but the old-fashioned way), Snyder revealed that Lex Luthor would be the one to tell Darkseid about Lois Lane being the key to Superman's downfall. Darkseid would succeed in killing Lois and Superman would fall to the ant-life equation, which would ultimately lead to the Knightmare future Batman kept seeing. Also, Batman would have felt guilty for Lois' death because, in Snyder's original take, the pair would have fallen in love with each other following Superman's death.