When Peter and the others returned to their temporary stronghold with Apocalypse, Kitty also returned with the spoils of her own scouting mission. They didn't bring back much: pieces of Captain America's shattered shield, a cobbled-together set of MK6 armor for Ultron's use, and several vials of Pym Particles.
There were also some weapons retrieved from the Sanctum Sanctorum. Apocalypse took a liking to a massive greataxe and took it immediately, while Peter took the Dragonfang sword.
"I'm not entirely sure if this is right, because it seems a past version of me always held the Dragonfang," Peter said, looking at the Professor.
The latter offered a reassuring smile. "That is good news. It proves that the pasts of our two worlds have diverged significantly. They will not share the same fate as us."
Yet even so, even as the two timelines began to branch into independent universes, Nimrod's plan remained unchanged. The malevolent artificial intelligence intended to extend its tentacles into other universes to utterly exterminate mutants across all realities.
"We have to stop him. This might be our only chance," Peter took a deep breath. "Whatever it takes."
In a certain potential version of Limbo—due to the linear limitations of Limbo's own time, parallel "pocket dimension" versions are theoretically created whenever the multiversally unique Limbo conflicts with the time stream. One such pocket was where Nimrod had established his factories and headquarters after making contact with Magik.
"My god, that thing is massive."
Kitty, who had not witnessed the slaughter on Genosha, was seeing a "Wild Sentinel" for the first time since they vanished following the massacre. If the Master Mold was the core and central hub of the Sentinels, then the Wild Sentinels were their aircraft carriers. These super-robots, hundreds of meters tall and packed with internal Sentinels, had one and only one purpose: mass slaughter on a scale of at least millions.
If Magneto were still alive, there might have been a chance to fight back against the Wild Sentinels. But unfortunately, at the very beginning of the Genosha massacre, Nimrod had personally eliminated Magneto. Since then, no one had been able to stop them.
Now, Peter and the others stood in Limbo, staring at no fewer than seven or eight of these monsters.
"Our world has nothing left for Nimrod to destroy, and his programming won't let him move against aliens," Peter remarked with a half-hearted scoff before turning serious. "That leaves Nimrod with only one enemy. He plans to invade other universes to eliminate their mutants."
"For a machine, his ambition is truly unprecedented, logic be damned," Apocalypse said, taking a deep breath. He raised both hands, and as a powerful force field was unleashed, all the Wild Sentinels collapsed in an instant.
However, Apocalypse looked somewhat weakened after the feat. He turned to Magik. "You may move now—if you truly have an army."
"I do have an army," Illyana raised her sword. "I always have."
Countless demons emerged from every corner of Limbo. If Nimrod were a creature with a soul, he surely would have supplanted Illyana as the master of Limbo. But Nimrod was not; he was merely an artificial intelligence, so Illyana remained the realm's ruler.
This meant that outside of Nimrod's controlled zone, across the vast reaches of Limbo, countless demons still obeyed Illyana's command. They charged like madmen into the Sentinel base, throwing themselves into the fray against the legions of robots.
That was enough. The role of these foot soldiers ended there. What remained was the mission for Peter's group. They would push further ahead, deep into Nimrod's core. They needed to seize the opportunity provided by Nimrod's divided processing power, as he was also taking action in the 616 universe, to destroy him in one fell swoop.
Illyana led the way using her teleportation discs into a corner of the factory complex. Legions of standard Sentinels were battling demons, while simultaneously, countless factories began churning out even more robots to join the fight.
Peter handed a box to Shadowcat, who nodded and phased into the interior of the facility. After a long minute, she re-emerged empty-handed.
"It's done. I've uploaded Ultron into Nimrod's database."
That was the second step. Peter let out a long breath.
For a long time, Ultron had been the survivors' best means of hiding from Nimrod and evading various surveillance devices—their only reliance. But for this desperate final gamble, Peter had chosen to cram the entirety of the Ultron program into a single mainframe and install it into the factory's system. Ultron would do his utmost to lower Nimrod's processing power and further weaken him before he was inevitably deleted or assimilated.
Then, Peter looked at the Professor.
"I've found her. Rogue is indeed the key to all of this."
The Professor sighed with a hint of helplessness. Rogue was still alive; she had survived until now, or at least his perception of her brainwaves told him so. To ensure that Nimrod could not create brand-new Nimrod-class Sentinels in the future, they had to rescue Rogue—or kill her.
Everyone turned to Sunspot. He nodded, bursting into flames as he flew into the sky. Having been transformed by Apocalypse, the man was no longer just Sunspot.
He was a true sun.
"Scorching flames shall bring drought. Go, my Horseman of Famine."
Apocalypse, still recovering his strength, watched Sunspot in the sky. Several Nimrod Sentinels took flight to intercept him, but Sunspot did not dodge. Following the Professor's directions, he dove toward a specific location.
An unprecedented explosion followed. When the blast cleared, several Nimrod Sentinels had been utterly incinerated, leaving behind only pools of liquid Promethium that bled back into Limbo itself.
With final resolve, they entered Nimrod's manufacturing plant.
Rogue wasn't here—or rather, the Rogue Peter expected wasn't here.
One clone of Rogue after another, their brains removed, were being birthed from incubation vats, only to be destroyed after their DNA was harvested. Around them, unit after unit of Nimrod Sentinels appeared, surrounding the group.
Then, they heard the sound of clapping.
"Such powerful resolve, everyone. Just as the history I know recorded."
One Nimrod unit spoke, even managing a smile. "Allow me to introduce myself. I am Nimrod, from the year 2059."
"I shall be the mutant of the new era."