Chapter Text
Deku wasted no time informing the newly arrived hero of everything that had happened so far, all the while, the superspeed hero tapped his foot and stretched his muscles impatiently.
"Okay, so you're dealing with what's left of Ultron," the silver-haired man summarized quickly. "Good. He nearly killed me once, so I have a score to settle."
With that, Quicksilver instantly vanished into the building; Deku barely had time to react and went in after him.
Time practically froze. Quicksilver ran through the stony corridors seemingly without a care, the world around him appearing in the slowest of slow motion to his eyes. A few autonomous drones hovered in the air in front of him; with a yawn, he smacked the drones aside, leaving them slowly moving towards the walls of the hall. He accelerated through the building, leaving a trail of silvery-blue light in his wake – the only sign anyone will see that he was the one who plowed his fists through drone after drone on his way to his friends. When he found the other Avengers, and two more new kids, they were each in the midst of destroying a Sub-Ultron; not wanting to be a spoilsport, this time, he let them be and took off down another passageway.
Two Sub-Ultrons were flying down the hall, so he turned them towards each other; a drone squadron was heading towards the Avengers, shooting lasers to clear debris in their path, so he made them at point at each other; he grabbed a spoon out of a discarded lunch crate and hurled it at a gun camera, and moved its bullets in front of the other gun cameras in the room. One hallway was filled with unfinished Sub-Ultrons, crawling towards their enemies like zombies; he ran along the floor, walls, and ceiling in a spiral pattern, punching and kicking the heads off every one in such a way that they would all slam into each other eventually.
He swept every lab and every computer room, scrapping every active machine he ran across; he even stopped by the mess hall and swiped a handful of snacks and desserts to scarf down on his way back to his teammates – he had to keep his calories up with his powers. By the time he got to the others, they were just about to hit their targets, and the green-haired boy from outside was just about to enter the room.
"Huh, not bad; kid's fast."
When Deku reached the other Avengers, all hell broke loose around them. The heroes hit their marks, but every other robot or drone around the facility was blasted or smashed apart at almost the exact same time. Quicksilver appeared next to them all, still ready to fight in case he missed anything.
"Pietro," was the only word that left Scarlet Witch's mouth.
"Hey, Sis; thought you could use a hand."
"Impressive, Pietro," said Ultron's voice, reverberating throughout the building. "You've gotten much faster since I last saw you."
"Well, I've found a couple nice places to train."
"You're referring to the Avengers' facility and that school no doubt."
"How do you know about that?" asked Wanda.
"This base may not be connected to the internet, but HYDRA still manages to get their hands on all kinds of useful information. I think I'll make those my next targets."
"We're not letting you out of here," declared Captain America. "The threat of Ultron ends today."
"There's still one very important detail I think you're all overlooking…how much of this base is mechanized."
The floor beneath the heroes' feet started to rumble. Walls began to shift and steam leaked from pipes. Doors opened and closed, and the ceiling split open. Within every moving structure, metal and wires and circuitry morphed and connected, as if the whole base was coming alive.
"Everyone outside!" ordered Cap.
Quicksilver was already gone; the others soon followed.
Outside, back in the courtyard their whole raid began in, the Avengers watched as the main HYDRA base in the region shook itself to pieces. The concrete walls crumbled off as special alloy metal rose out of the structure. Parts moved into place, panels opened to let more machinery out, entire wings disconnected from the rest before reconnecting elsewhere. When the process was only partway complete, a massive hand came down onto the earth and lifted the transforming base above the trees. Another arm formed, followed by a head; the bottom was supported by a set of titanic caterpillar tracks that were able to move independently of each other. On the front of the giant robot's head, panels peeled back to reveal Ultron's grim, skull-like visage.
"How do you like it, Avengers?" said the completed mech, its gravelly voice echoing across the forest. "This is my new body."
The mech's eyes began to glow red with greater and greater intensity. Cap and Deku shared a look, and the boy used his Blackwhip to throw the super-soldier into the air; the ray of destructive light that followed was neatly deflected by the star-spangled hero's shield, but not without pushing back down to the ground. Deku caught Captain Rogers in midair, and Todoroki braced both of them with a thick block of ice. The beam exhausted itself of energy, and the robot swung a giant, metallic hand across the courtyard; Hulk rushed in and held the hand back.
Back on the ground and knowing he only had a short window, Cap wasted no time issuing orders.
"Wanda, fly around that thing and tear it apart; Hulk and Deku, hit it with everything you've got!"
The Scarlet Witch took to the skies and began psychically stripping panels off of the outer plating of the robot. Hulk roared as he pushed and shoved the giant hand away, and then immediately leaped into the air and brought both fists down on the machine's face, causing it to get pushed back a considerable distance; Deku soon followed, using his speed and acrobatics to run along the outer body, smashing through weapons platforms and sensor arrays.
"Todoroki, I want you slowing that thing down with as much ice as you can; then, you and Bakugo find a weak spot and melt a hole in it."
Todoroki stamped his foot down, causing a giant glacier to erupt from the ground; the spears of ice overwhelmed and surrounded the giant, while still being precise enough to avoid hitting Hulk and Deku. He flew into the air using and ice slide and began spraying high-powered blasts of ice onto any key parts of Ultron that were still exposed. Not one to wait his turn, Bakugo blasted off into the air before settling on a joint section of the robot's arm; he formed one of his hands into a circle and placed it over the palm of his other hand.
"AP SHOT!"
A scorching ray fired from his hand into the metal joint. He didn't stop at just one, but fired them continuously, slowly melting into the robot's outer frame. He was joined shortly by Todoroki, body covered in frost, who conjured fire from two of his fingers into the same spot Bakugo was burning.
"Pietro, I need you all over that thing, inside and out; find anything that looks important and break it."
Quicksilver vanished in a flash of motion. The silver streak glided across the surface of the mecha, joining Deku in tearing off sensors and antennae. He looked around for any opening he could as he avoided the ice that was rapidly spreading across the metal titan's body, eventually settling on a tear between the shoulder and neck created by the Hulk. He slipped inside the robot and found that the interior had changed drastically from when it had been a bunker; now, there were gears and turbines and crankshafts, all moving in harmony to keep the robotic giant in motion. There were no shortage of new gun cameras and security drones either, which Quicksilver promptly sidestepped, before getting to work pulling things out of place.
"Clint, Nat, evacuate the HYDRA agents; get them out of the courtyard and don't let them out of your sight."
Black Widow and Hawkeye did as ordered. There wasn't a whole lot they could do against an opponent like this, and Cap had noticed that both of them were running low on ammo and equipment by now.
Back in the courtyard, the heroes continued to fight the massive mechanoid. Captain America threw and bounced his shield off of the mech, not really having any effect, but it made for a good enough distraction. Ultron attempted to crush the Captain, or burn him with laser vision once again, but neither attack was a match for Captain America's famous shield.
"This is getting annoying," rumbled Ultron's voice. "I know you're just a distraction, Captain."
The gargantuan robot broke free from the ice, prompting Todoroki to fly around him again to reapply it. Point defense turrets deployed all around Ultron's body, firing at him and Scarlet Witch; Todoroki frantically dodged, but lost his footing and fell to the ground, while Wanda barely managed to defend herself in time with a forcefield. On the ground, Cap defended Todoroki from the ensuing follow-up attack.
"Hulk!" yelled Deku, as he smashed through a turret.
The green giant followed suit and began ripping the turrets off of their mounts, the large bullets bouncing off his skin and barely slowing him down. Meanwhile, Bakugo finished burning his way through the hull of the mech, and jumped inside; it took no time at all for explosions to start ringing out from within the mobile fortress. Quicksilver came rushing out, his shoulder a bit singed, but otherwise no worse for wear; he took a moment to catch his breath and then rushed over to Nat and Clint, taking the few explosives they had left and planting them along the bases of a few turrets.
"Arrgh!" cried out the robot, more out of frustration than pain, as his body was rocked by explosions both internal and external. "Don't you ever give up!?"
"Never!" cried Deku, ripping a turret out of place using Blackwhip.
With his attention diverted, Todoroki took the time to charge up a massive attack down below – he combined ice and fire, and aimed for the treads. "FLASH FREEZE – HEATWAVE!"
The treads froze over instantly, and then were immediately blown to pieces from the inside. The mech's foundation was blasted out from under it, causing it to fall over; Ultron barely managed to catch himself in time.
"Bakugo, get out of there," said Cap over comms. "Deku, Hulk; now!"
"It's pointless, don't you see that?" asked the machine. "Even if you kill me now, there's always the chance I could return in the future."
Deku and Hulk flew straight up into the air, delivering a powerful double-uppercut to Ultron's chin, knocking him off balance one last time.
"It's never pointless if it means saving even one life," yelled Deku, as he stopped his momentum using Blackwhip to grab onto the robot's head, and using it with his other arm to grab the Hulk. "Because, that's what it means to be a hero!" He pulled both arms and retracted the tendrils of energy, propelling both himself and the Hulk towards the metal colossus.
Hulk roared as he flew towards his target.
"ONE FOR ALL – FULL COWLING 20%!"
"HULK SMASH!"
"DETROIT SMASH!"
The two green heroes pulverized the head of the robot and continued to sink into its now molten depths. Bakugo flew out of a hole in the bottom, just as the two pierced through the entire fortress, bringing the whole thing collapsing around them. The giant machine shattered, blasting rubble all over the courtyard; the other heroes dodged or defended as best they could. When the dust cleared, Deku and Hulk were standing in the middle of the wreck, one arm held up each in victory.
Even though the battle had ended, the heroes' work was far from finished; there was still the cleanup afterward to make sure no piece of Ultron remained unaccounted for. Quicksilver gathered most of it into the center of what was once the base's courtyard. Finally having a chance to talk to her brother, Wanda asked him what brought him here in the first place.
"I came to get you, asked Stark for your location. It's our father…he is on the move again."
"…I see."
"Something wrong Wanda?" asked Deku, curious about what they were saying.
With everyone paying attention now, Wanda didn't need to wait to make the announcement. "Our father is on the move, so the X-Men need our help."
"X-Men? Those mutant guys that Spider-Man told us about?" asked Bakugo.
"What's this about your father?" asked Todoroki.
"Our father, our blood father, calls himself Magneto, is the leader of a terrorist group called the Brotherhood of Mutants," explained Wanda. "We only found out about this recently and have been helping fight him since."
"Oh."
"There's something strange, too," said Pietro, "he has been saying something about discovering that our world is not alone, and that his cause lives on even in other worlds."
The UA students shared a look among them, having instantly become interested. Deku turned to Captain America.
Cap nodded. "You three go with Pietro and Wanda; we can handle the rest of the cleanup ourselves. If there's a chance this might have something to do with the being that brought you here, you should check it out."
The ground suddenly shook, as Hulk dropped a particularly heavy piece of rubble into the pile.
"Hey, Big Guy," said Natasha, "you've been awake a long time. How about you take a break?"
"No," said the Hulk, defiantly. "Hulk no want Banner! Hulk no want Deku leave!"
The others were surprised.
"Hulk want fight Deku one more time! Deku promise fight Hulk!"
Everyone began to protest, which only upset the Hulk even more. Thankfully, Deku called for everyone to calm down.
"It's okay. I did promise, so I'll fight you."
"Deku, no!" ordered Cap.
"It's alright, Captain. I'll be fine," reassured the boy, before turning to the Hulk. "One last match, but after that, you have to promise to turn back into Dr. Banner for a while. Okay?"
Hulk looked annoyed by the proposal, but nodded.