Drug

"Jarvis, how are things going so far?" Tony Stark mumbled, continuing to fly over the dilapidated buildings.

"Over 90% of the city citizens have already been rescued," Jarvis articulated with his robotic voice. Tony Stark nodded subtly. "However, Steve Rogers still didn't appear. I can't find any traces of him in this city."

"Steve, where the hell did you go?" Tony whispered to himself, landing atop one particular rooftop as to overlook the ruins of the city. "Jarvis, what about Ultron?"

"His actual body hasn't moved from the spot yet, still protecting that machine." Jarvis retorted, and Tony sighed profoundly. He understood what he had to do, but could he win against this creature with just Thor's help?

After all, he was the only one to answer his signals.

"There's no other way."

-

"I don't understand… why are we hiding here?" Pietro asked with a frown, looking through a hole in the window. The entire ground was crumbling in front of his eyes. He should be trying to stop Ultron right now, instead of waiting in this hole for the downfall of humanity.

"Didn't you and your sister want revenge? I am giving this opportunity to you right now," Nagato stood in the building's corner, also peeking through the hole in the wall.

"Revenge? Are you mad?" Pietro frowned deeper, both his eyes sparkling with anger. "I knew something was wrong with you. Do you really believe I care for revenge right now? The world will get destroyed if we don't stop Ultron."

As his words echoed through the vacancy, he prepared to leave. He hated Avengers with all his heart, but with their help, there still was a chance to stop that robot.

"I already told you I was going to deal with him myself." Nagato sighed, extending his hand towards Pietro. "I knew this would happen. You and your sister still don't have the right mentality to be my pawns, but that will change today."

"What the hell are you talking about?!" Pietro halted his step, turning back around. His face bulged with veins as he grabbed Nagato by the collar, not caring anymore about his singular powers. "If you wanted to stop Ultron, you would have done that right away! Not hide here like a rat!"

Nagato didn't answer. He simply continued to stare deeply into Pietro's eyes, as if regarding the foe's soul itself. Pietro has also felt pain, however, even he couldn't understand Nagato.

"It's a pity I will have to sacrifice you for the sake" Nagato eventually mumbled, noticing a crimson figure settling on the nearest building. Tony Stark finally appeared, signifying the beginning of the plan.

Before Pietro used any of his powers, Nagato grasped the rod and plunged it into Pietro's stomach. His eyes dialed from the pain, not excepting such a turn of events.

Pietro tried using his powers to promptly retreat from the place, yet only weakness filled his insides. Looking up, perpetual darkness met his gaze, subtly lit up by two enormous violet eyes. It was like staring at the death itself.

"Goodbye, Pietro," Nagato said, penetrating the rod deeper into the youth's bondmen. While the unusual effect of the rod still distracted Pietro, Nagato took something out of his pocket. It was a tube filled with dark liquid inside, which Nagato has taken from the collector during his stay on Knowhere.

Forcing Pietro to open his mouth wide, Nagato broke the tube and made sure the former subordinate swallowed all of its contents. The liquid took immediate effect. Pietro's entire forehead got painted with veins, his eyes taking the shade of black.

'As expected. The drug is truly magnificent.' Nagato noted, storming through the memories of that collector. Taneleer Tivan wasn't dumb, for he understood how hard it would be to collect all the Infinity Stones.

That's why he began the creation of this drug, eventually hoping for mass production. The drug ultimately enhanced every cell in the body, making the person gain immense physical strength.

However, its side effects were far too great. Not only would the person go into berserk mode and utterly start killing everyone on his path, not even caring whether they are allies or enemies, but the user would also ultimately die.

Tivan regularly researched on how to improve the drug, but all was a futile struggle.

'However, this time the side effects of the drug are more relevant.' Nagato released Pietro from his grasp, taking a few steps back. While Pietro still hasn't completely lost his mind, Nagato summoned the creature with the ability to become invisible.

"AHHH!" Pietro suddenly shouted, his entire skin bulging with veins. He was a completely different person from the former himself. No... it couldn't be called a human anymore.

Breathing heavily, Pietro surveyed the room with his dark eyes and disappeared from his spot after not finding anyone. In an instant, he arrived on the rooftop of another building, searching for any signs of anyone, craving for blood.

Enhanced by the drug, Pietro's speed magnified multiple times. He has reached the perfection of his powers. Even Nagato got quite fascinated. Still, Wanda could become a much more valuable pawn.

Taking in a deep breath, Pietro rushed through the city's empty streets. A normal eye wouldn't be able to see anything, except thousands of imprints constantly appearing on the cement ground.

"Mhhhah...hah?" Eventually stopping in one particular area, Pietro locked his gaze on an old man sitting in a car. He smiled crazily, gibberish escaping from his mouth. Barely a blink later, Pietro already stood on the hood of the car as his shadow loomed over the man.

His hand formed into a fist and he broke the window, causing the civilian to exclaim in fright. Grinning madly, Pietro almost got his hands on the man when a kick suddenly landed on his ribcage.

Pietro flew multiple feet away and hit the other car, yet his face didn't convey any signs of pain. He smiled even more deeply. Tony Stark hovered over the ground, holding the frightened man within his grasp.

"You are that mutant from Hydra, aren't you?" Tony Stark asked, whispering something to Jarvis. While Pietro still didn't move from his spot, another robot shuttled from the south and took the man instead. "What the hell happened to you?"

Seeing his prey just casually being taken away from him, Pietro finally acted. Tony Stark, understanding that talking wouldn't do any good, braced himself for the upcoming battle.

As the fight between the two began, Nagato watched everything from the rooftop, waiting for the real fun to begin. Silently. Nonchalantly.