During the Secret Wars, Galactus and the Beyonder killed each other, taking the life of Mr. Fantastics at the process. After that the heroes and villains residents of the Battleworld lose their best chance of returning to Earth.
In the later years, many of the villains continued to war, other casualties were Bulldozer, Captain Marvel, Cyclops, Doctor Octopus, Kang, Magneto, and Spider-Woman. Five years later, the group achieved peace, Doctor Doom built a replica of his castle on Latveria, and Hulk becomes a hermit, contemplating how they might return to Earth. The remaining heroes and villains lived on peace on a small community, and many of them married and had children.
When Bravado, son of Thor and Enchantress celebrated his 18th birthday, a group of teens, led by his step-brother Malefactor, seemingly killed Dr. Doom. Malefactor recruited Chokehold, Gator, Klaw, Moleculon and Raze for achieving his goal of taking over Battleworld.
Bravado refused to join Malefactor's group, he informed his friends Crusader, Firefly, Mustang and Torrent, suddenly they form an alliance to stop Malefactor's plans.
After the rebels nearly emerged victorious on the conflict, the adults joined to the conflict. The return of Hulk, added with the return of Dr. Doom, who faked his own death, made them came back to punish Malefactor, ending with the conflict.
Hulk used the 30th century technology of the deceased Kang for adding it to Thor's hammer, Mjolnir, in order to open an inter-dimensional portal for returning to Earth.
Uatu the Watcher appeared, warning the heroes that something bad that would happen if they returned to Earth. Later the young heroes accessed the machine, traveling to Earth for the first time, only for find the planet overrun of Sentinels.
The five young heroes agreed to stay on the Earth as the Battleworld Avengers, in order of liberating the world from the Sentinels menace.