AVENGERS (Earth-8545)
Chronology
First appearance: Exiles (1st series) #20
All appearances: Exiles (1st series) #20-22, 34, 66, Exiles: Days of Then and Now #1, Spider-Verse (1st series) #1
The Legacy Virus ravaged Earth-8545 an
d, by 1995, its impact was considered comparable to the bubonic plague. Initially, the disease claimed only mutants, such as Illyana Rasputin who died at 12 years old on this world. As in many other realities, there was little political goodwill for the mutants afflicted, with some surmising that the disease may have been the price of the gifts they possessed. As on Earth-616, the disease did not remain a mutant-only problem and soon even humans with latent mutant DNA were affected, with entire families and upwards of hundreds of thousands of people being wiped out by the epidemic. When the New Mutants member Cypher contracted the virus, a veritable death sentence, his friend Warlock, the techno-organic alien, sought to save him. He merged with Cypher, hoping the merger would expunge the virus, but instead he merely mutated the virus.The combined Cypher/Warlock became “patient zero” for a new race of beings called the Vi-Locks. The Vi-Lock infection was spread by touch and infinitely more contagious than even the legacy virus. The afflicted retained their intelligence but became part of a hive-mind called the Network, dedicated to the consumption of other life forms. Gambit and Jubilee were the first heroes to be infected by Cypher but most of the world (approx. 70%), including most of its superhumans, would go on to be contaminated. These Vi-Locks had a hierarchy of their own and the mutant Forge ascended to their leadership, with his natural intuitive understanding of technology. Ruling from their citadel called the mainframe, the Vi-Locks continued with their mission to consume and infect all life on Earth.
The remaining heroes, the Avengers, set up a safe haven in Las Vegas, Nevada, where they attempted to protect the remainder of humanity. They used their telepaths to communicate with each other so their comms could not be tracked by the Vi-Locks. Despite this ingenuity, things were decidedly bleak before the arrival of the reality-hopping Exiles. The Exiles appeared on the perimeter of Vegas and encountered a group of young Vi-Locks attacking and infecting a group of children who had snuck out of the safety of the city. The experienced team managed to save the children, though they were still infected and escaped into the city, unaware they were being watched by Hank Pym and Spider-Woman. 
The Avengers briefly incapacitated the Exiles but, once they realized they were uninfected and safe, Dr. Pym and Spider-Woman introduced themselves. After a brief explanation as to who the Exiles were, Pym explained just how dire the situation was and that, essentially, he could not figure out why the Vi-Locks had not already destroyed him and the other survivors, as they possessed the power to do. The Avengers main priority now was to find a vaccine. Pym had devised an antidote based on DNA from mutants with healing factors; however it merely slowed the progression of the virus and was not powerful enough to function as a cure. Pym demostrated this to the Exiles with the children they had rescued. Blink suggested they find patient zero, Cypher, so they could synthesize a cure from him. Pym had assumed he was already dead. Blink assured him that Cypher was very much alive but in the mainframe.
Pym devised a plan which would involve one group distracting the Vi-Lock forces outside the Mainframe, while another smaller group infiltrated it. The infiltrators needed to be infected with the “original” Warlock virus to avoid detection, which would take approximately four days. The Avengers made their new guests at home, with Powerfist flirting with Nocturne and Spider-Woman and Sunfire starting their romance. Morph was skeptical about Pym's plan and devised his own “plan b.” He had noticed there were no Asgardians among the heroes or infected. Seeking out Rachel Summers, who was the most powerful psi the Avengers had, he hoped he could get her to telepathically contact Asgard and ask for help. Both Rachel and Morph remained in Avengers compound when Pym's plan was commenced.
Blink and Nocturne of the Exiles and Spider-Woman and Havok of the Avengers teleported into the Mainframe to find Cypher, while the rest of the Exiles and Avengers created a distraction. The mission was a disaster, however. The assault team was overwhelmed by the Vi-locks with Blob becoming infected. The stealth team were discovered by Forge, who simply killed Cypher when he realized that was who they were searching for. 
Worse, he managed to infect Blink. Luckily, despite her infection, she was able to teleport herself and both teams back to the safety of Las Vegas before collapsing. Her lover Mimic carried her to the medi-lab for Pym to take care of her. As this was going on, Blink was delivered a message by the Tallus: the Exiles had failed and the only option to contain the Vi-Lock virus was to destroy the Earth. The Tallus had told Blink that in a month, in retaliation for their attack on the Mainframe, the Vi-Locks would consume the remaining humans and then go to space, where they would assimilate more lifeforms. In a thousand years, all life in the universe would be Vi-Locks. Dr. Pym was not surprised and had been anticipating that things might get to this point for years. He was prepared to sacrifice the planet to save the rest of the universe.
The Vi-Locks had stockpiled nuclear weapons to prevent them from being used against them. Pym's plan involved hitting their armament with a nuke of their own, which he believed would have the destructive power to split the planet in half. There was some debate as to who would pilot the ship but, ultimately, Exiles member Nocturne insisted it be her, as she was the best pilot. Her teammate Mimic did not agree and knocked her out before she set off and took her place.
Meanwhile, Morph's own plan had succeeded; Rachel Summers had managed to reach Asgard telepathically and the gods had answered her prayers. 
The king of the gods, Odin, offered the Avengers their blood to synthesize a vaccine. Miraculously, in mere moments, Pym was able to create a vaccine, thanks to the regenerative powers of the gods’ blood. With the salvation in their hands, they now had to stop Mimic from destroying Earth but were unable to reach him. With no other choice, Spider-Woman on Pym's instruction informed the Vi-Locks that one of their members had gone rogue and was trying to destroy the planet and that the Vi-Locks needed to stop him. Veering on the side of caution, Forge dispatched some of his number after Mimic, though they were no match for Mimic and his robust powerset. Meanwhile, Blink started to wake up, becoming herself again thanks to the cure. After she was told what was happening, she teleported to Mimic. Knowing she was safe and there was now a cure, Mimic flew the ship with the nuke into the sky, where it detonated while Blink teleported them to safety.
Eighteen hours later, the Avengers, the Exiles and the Asgardians celebrated with an elated Pym repeating to anyone who would listen about how incredible it was that the Asgardians' blood's healing properties would allow them to save the world. As the festivities continued, the Timebroker, the exiles mysterious benefactor, appeared on site, claiming that Blink had completed her personal mission and was being returned to her timeline, while the others were to go on to another mission with their new team member, Magik. [Exiles (1st series) #20-22]
With the Exiles gone, the Avengers continued with their mission of curing the world. While the other Asgardians appeared to have departed, unsurprisingly Thor remained among their number, bolstering their power with his added muscle. They had some successes at this point, inoculating 80% of the infected and notably curing Captain America and Juggernaut. The last thing that was expected was for the Avengers to see the Exiles again. Nocturne and Sunfire had been separated from their teammates due to a curse by a vampirized Union Jack 
[Exiles (1st series) #32] and ended up back on the “legacy” earth. They were soon found by the Avengers. Spider-Woman was overjoyed to be reunited with Sunfire and the two quickly rekindled their romance, becoming much closer this time around. Beast analyzed their appearance, informing Nocturne that it was very much a temporary phenomena and that they would eventually return to the Exiles. As this would be at an uncertain point, he told Nocturne to try to enjoy her time here. Sunfire and Nocturne also helped the Avengers in their efforts to cure the Vi-Locks, serving on Powerfist's squad. After a mission, Nocturne explained to Sunfire she was concerned about her relationship with Spider-Woman. Nocturne could see that Spider-Woman and Sunfire were falling in love but knew instinctively it couldn't end well, as they would eventually become unhinged from time/reality again. As the two friends debated back and forth, Spider-Woman was listening behind a tree. Spider-Woman confessed to Sunfire later on that she had overheard the conversation and wasn't sure that Nocturne was wrong; maybe it was better for them to keep their distance to avoid being hurt? Sunfire was adamant she was not giving up the relationship as it was the happiest she has been in her life. The two agreed to persevere until their time together was finished.
Thirteen days after this conversation, Spider-Woman and Sunfire got back from a mission being led by Captain America. Spider-Woman had butted heads with him and was venting to Sunfire when Sunfire disappeared, returned to her life as an Exile. [Exiles (1st series) #34] Sunfire would go on to fall in battle on one of the Exiles’ missions. She was only 24. On the insistence of her teammate Morph, her body was brought to Mary Jane for burial. The Avengers and Exiles had a Christian ceremony in the Las Vegas desert for Sunfire. Mary Jane thanked Morph for bringing Sunfire back to her, even though she personally thought Mariko should be returned to her home reality. A graveyard/monument would later be built around Sunfire's grave with other important deceased being laid to rest there. [Exiles (1st series) #66]
Following the creation of the vaccine, the Vi-Locks did change tactics. No longer looking to assimilate humanity, their intent was now to destroy them so they could survive. While the heroes did prevail, the cost was immense, with many dying in the conflict including the hero Daredevil. Mankind marked their final defeat of the Vi-Locks, with an annual celebration called V-Day. On the first anniversary of this event, Powerfist was recruited to join an off-shoot Exiles team tasked with liberating an alternate Earth from a tyrannical version of the Hulk. His fate is unknown. [Exiles: Days of Then and Now #1] His teammate Spider-Woman went on to lose her life sometime later against the dimension hopping villain Morlun while he was hunting Spider-Men and Spider-Women across the multiverse. [Spider-Verse (1st series) #1] A loss of three of their premier heroes would be catastrophic for any world but, given the resilience shown by the Avengers of Earth-8545, they are sure to rebound.
[Notes: The threat of the Vi-Locks on Earth-8545 may be over but some escaped to Earth-616 as outlined in Civil War Battle Damage Report #1. A contingent were brought to Earth-616 by the sorcerer Yandroth and attacked Ireland, infecting some local residents. They were repelled by the Irish superhero team, the kinsmen and the hero Lectronn and said to have left Earth. What specifically was intended with “left Earth” (space, back to their home reality, another dimension etc.) was not made clear.]