Angst
You get killed, walk it off.
Pietro panted, struggling only slightly to catch his breath as he listened to the Captain, holding his side that caught in a sting with each inhalation. The words were meant to be both dramatic and inspiring to the team, but Pietro only laughed quietly to himself; walking it off wasn't an option for him. He would run. He would run until there were no more robots in Sokovia. He would run until Ultron was dead and he and Wanda could live in peace. If that means we would live amongst this team, then that wouldn't be so bad, he thought. If it meant that he and Wanda could be free, Pietro would run forever.
It's my job.
The last time that Pietro and Wanda would see each other is when she stood firm at the drill in the center of the city, refusing to step down at her brother's insistence. He tried to use his line of being the older of them, but she simply laughed him away with a shoo and a smile that he would carry with him as he finished the mission. That smile had brought him though so many hardships and so much pain that he had come to rely on it, even though he may not have realized it. That smile was there for him when their parents were lost, and even though it may have been forced and weak, it was enough. The smile she gave now would definitely get him through anything.
Is that the last of them?
They were almost there, with the people of the city loaded on the rescue boats, and all that was left was for Tony and Thor to disintegrate the rock as it continued to raise higher and higher. That was all that was left, Pietro hissed to himself quietly and under his breath, seeing Barton struggling to free the boy from the rubble as Ultron fired from the jet and moved straight for them. The archer wasn't going to make it, and Pietro couldn't just stand by and watch when he knew that he could help. With a deep breath and pushing to his limits, he ran. You saw him run and you tried to yell out for him to stop, but he didn't hear you; you barely saw him for more than a silver wave as Clint disappeared within it and reappeared only a few feet away. When it was done in just a matter of seconds, Pietro looked at Clint and turned to you with a smile, successful when even he himself thought for just a flash of a second that he might have been too late.
You didn't see that coming.
"(Y/N), you see? I told you that I could make it," he smiled, affording enough time for a fast hug before securing people in their seats. "Do you always worry so much?"
"Listen here, Flash, we've only known each other for a few hours now, but let's get one thing straight," you replied, trying to hold an angry expression but failing, "yes. Yes, I do worry that much. Just so you know what to expect from now on around here."
"You're funny. I think that you and I might become fast friends."
"You're the fast one around here, so I don't know about that," you smiled back to him, pausing at his striking features that you hadn't taken the time to really look at until now. He was so young, and so full of life, and his eyes sparkled with mischief. "But friends? Yes, of that I'm certain." You took a few steps away towards a small group of children who had been left without an adult, kneeling down to them to get their names and put them at ease when he spoke again.
"I look forward to that, (Y/N). I should go check...on..."
When his words broke away, you spun on your bended knee and looked up at him, seeing his face growing pale, the color from his lips completely gone, and his body beginning to shake. He dropped to his knees at your side and grabbed his head, screaming with a sound that you knew you would never forget; it echoed through the desolate city and beyond into the sky, without limits to the pain that carried. The absolute fear and desolation in his eyes was immediate and powerful enough to send tears to your own without readily knowing their cause; but in just a few seconds, you wanted nothing more than to forget.
Pietro stood and ran from you before you could react, leaving you with Steve and Clint looking on with sorrowful expressions, mimicked by the citizens around you who had known the twins before this day. None of you knew if Pietro would be returning, but you had no way to catch him; all you could do was wait, but as the rock suddenly began to groan and shift beneath you, the waiting was over before it began.
It's been a long day.
"If you stay here, you'll die," Ultron told Pietro, as if the young man even cared anymore. Without his sister at his side and never to be there again, he had no will to go on, and death wasn't a fear that he continued to carry. He almost welcomed it now, kneeling in front of the metal man that had taken his only remaining family from him.
"I just did," Pietro spat, "do you know how it felt?" With every last ounce of strength that he had, Pietro clasped his hands together and raised them above his head, slamming them down onto Ultron's chest with a swift and vengeful hit to spread the metal chest apart. He looked for just a second to find it; the clockwork-like heart at its center, reaching in and ripping it from from the cavity as he watched the light die from the robot's eyes. He felt no satisfaction. He felt nothing anymore. He was alone and had no purpose without her.
"It felt like that."