The titular heroes (Kyle Ratner and Hal “Parallax” Jordan versions) take on Thanos, Cyborg Superman, and Terrax.
Cyborg Supes invades the 616 and meets Surfer, and at the same time Terrax shows up in Kyle Ratner’s neighborhood. After the “hello fight to meet you” introductions, Hal Jordan brings Kyle and Surfer together and the threat to both universes is squashed.
As with most of these comics, this is for superfans of the characters only. Nothing here matters to the official 616 timeline.
But, something here DOES matter to the DC/Marvel timeline–such as it is. A box appears in an alley at the end, and it will serve to kick off a big Marvel vs. DC series event in 1996.