Steppenwolf's Motivation and Fate

Prior to Justice League, there were reports that the relationship between Steppenwolf and Darkseid would be different from their comic book relationship, with Steppenwolf as nephew rather than uncle. The theatrical cut debunked the reports, but only after the reshoots.

Steppenwolf was originally presented as a disgraced general who was Darkseid’s nephew. But it goes further than that. Steppenwolf is after the Mother Boxes, not only because they form the Unity and are the key to destroying everyone, but because they actually contain the essence of Heggra, who’s Steppenwolf’s mother and Darkseid’s sister in the DC Extended Universe.

Deleted Justice League scenes actually contain conversation between Steppenwolf and his Mother (once the Unity was formed).

Also, Steppenwolf wants to use the Unity, but not for Darkseid. He wants to use it to take away Darkseid’s power. He assumes the role of a usurper, and intends to return to Apokolips with the power of the Unity. He obviously doesn't succeed. Nonetheless, this would be a more interesting backstory than what we wound up with.

The fate of Steppenwolf is also revealed in a deleted scene. The boom tube that opens in the end and takes the supervillain and his Parademons away sends him to Apokolips, where Darkseid quickly kills him. So the DC Comics big baddie was supposed have a second cameo in Justice League.