The Civil War was one of Marvel's most explosive events, pitting the heroes of the universe against one another over the possibility of registration affecting the entire hero community. But although it was a destructive event, one reality introduced in the multiverse revealed how bad things could have gone.

In Marvel 2-In-One #7 by Chip Zdarsky and Ramón Pérez, a variant of Peter Parker was introduced who'd been embraced a very dark path as the Spider once his world's version of the Civil War took a decidedly darker turn.

RELATED: Avengers: An Ancient Marvel Villain Just Demolished Earth’s Mightiest Heroes

Spider-Man Variant Civil War 1

In the core timeline of the Marvel Universe, the Civil War event was particularly damaging to the life of Peter Parker. Serving as a member of the Avengers by that point, Spider-Man found himself torn between the leaders. Eventually taking Tony Stark's side in the debate about registration, he willingly revealed his identity to the public on live television. Although he was somewhat shielded by his status as an Avenger, it brought havoc to his personal life. When he switched sides to support Captain America it only got worse, eventually even building to the near-death of his Aunt May, and the events of One More Day to reverse his revelation -- albeit at the cost of his marriage to Mary-Jane.

However, things took an even darker turn on Earth-TRN799. In this world, the conflict soon escalated far beyond the United States. The two sides refused to back down at all, and more of the world was ravaged in the process. Eventually, Spider-Man took it upon himself to end the crisis -- namely by ambushing both Tony Stark and Steve Rogers. Parker murdered Iron Man, and defeated Captain America, imprisoning the former hero. Accepted and embraced by the remaining population, this mentally-cracked Spider-Man embraced his dark side -- becoming known as "the Spider" -- and became the undisputed king of the Mad Max-esque remains of New Jersey.

RELATED: Avengers Anatomy: The 5 Weirdest Things About Black Widow's Body, Explained

Spider-Man Variant Civil War 2

This version of Spider-Man was encountered by the Thing, Human Torch, and Doctor Doom of Earth-616 during the multiversal travels looking for their Reed and Sue. Alongside his ally -- this world's one-eyed Doctor Strange -- this Spider-Man quickly proves himself a bloodthirsty and brutal variant of the classic wall-crawler. He's taken to wearing Captain America's mask almost as a trophy of his "victory," and forces Grimm and Storm to compete in a death tournament for his amusement (and to distract the public from their difficult lives rebuilding society and defending themselves from the Reavers of this world). When the heroes escape (killing Doctor Strange in the process), Spider set out to murder them. But thanks to an intervention by the Invisible Woman, they were able to defeat the Spider and escape.

Even if he's a largely throw-away character in a series more focused on setting up the reunion of the Fantastic Four following the events of Secret Wars, the Spider is a deadly reminder of just how bad the Civil War between heroes could get. If the conflict were to fully have gotten out of control, then it might have fallen to someone like Spider-Man to save the day. But even the innate heroism of that character can seemingly be broken if the world is twisted enough -- and the grim fate of his people and his world leave a bitter memory of just how dark a variant of Spider-Man can become -- and what kind of world it would have to be to do so.

KEEP READING: Marvel's Prehistoric Avengers Face the MCU's Next Super Team in Eternals: Celestia