We are on the third part of Injustice 2's story trailers, titled 'Shattered Alliances' and while this trailer doesn't give us too much, it does show off Black Adam!
Part 1 of the Shattered Alliances story trailers revealed how Superman became the Earth's greatest threat and part 2 focused on the alliances that were built in the wake of the threat (as well as new fighters!). With the release of part 3 (below) we get to see Supergirl's side of the story.
In the trailer, we see Supergirl fighting Black Adam and Superman. On top of that, we see Batman and Catwoman nearly facing off against Superman.
Injustice 2 is set to release on May 16th, for the Xbox One and PS4.