Wanda was getting the hang of murdering robots when she felt it. Pietro was dead. She collapsed to her knees and howled as her magic shot out, killing everything in range. Pietro was dead. Her brother was dead. Never had she felt so much pain.
Even when Hydra experimented on them. She had felt pain similar to this when her parents died, but at least she had still had her brother. Without Pietro, what more did she have? Pietro was dead.
Hate and rage coursed through her veins. It wasn't a foreign feeling. For so long, she carried rage and hate for Tony Stark. Now, now it shifted to a new target; Ultron. "...You are an Avenger." Oh, she would be avenging all right.
"Wanda, if you stay here, you'll die." Don't pretend you care. You cowardly monster.
"I just did. You know what that felt like?" She used her magic to pull out the heart, still pulsing as she crushed it.
"It felt like that." Ripping out his heart did nothing to ease her pain. If anything, it made it worse. Without the rage and hatred, Wanda was forced to acknowledge the emptiness. Pietro was dead. Her brother was dead. Her brother was dead. Soon, I'll join him. Vision didn't let her.
All the emptiness inside you
Is hard enough to fill
Without a sense of purpose
-Round and Round
-Imagine Dragons