Beneath Avengers Base, there was a vault. Like the Mansion Prison inside the Snow Globe placed at the center of Avengers Base, it had been shrunk with Pym Particles and used to store various dangerous creations. It was piled with all manner of the most dangerous items the Avengers had managed to find on Earth-616.
For example, there were the two bodies of Legion Ultron—one blasted apart by Tony with intense heat, the other stripped of its computational core by Shadowcat. The Adamantium forming those bodies had been bluntly named "Stark Adamantium" by Tony, to distinguish it from the Proto-Adamantium that formed Captain's shield and the True Adamantium within Wolverine.
There were also the remaining three Super Adaptoids. There had originally been four, of course, but one had been modified by Pym into Ultron IV's mainframe and used against Nimrod. It had then been destroyed when Peter tore Nimrod apart with Space Slash.
There was also the corpse of the Original Human Torch, Jim Hammond, kept inside an airtight glass display case to prevent him from igniting upon contact with air.
There were other special items as well, such as the Wrecking Crew's Magic Crowbar. The crowbar had been granted wondrous magic, and Thor, who had only recently returned, had examined it and confirmed without a doubt that it was Loki's handiwork. Loki had cast magic on the entire crowbar similar to that of Mjolnir; aside from the Wrecking Crew's leader, Wrecker, no one else could lift it.
The four members of the Wrecking Crew had gained their superpowers through the powerful magic on that crowbar. If Wrecker had not shared his magic with his underlings, he himself could have become even stronger.
At that moment, Avengers Ultron stood before Jim Hammond's corpse. To his left were the two wrecks