Who lives
Five years. Five years since Pietro had seen his sister smile. After Stark got back from space, Wanda had given up. Nobody- not Nat, not Steve, not even Pietro- coupd help her.
Vision had died, then Sam and Clint's family were snapped. Wanda had loved Clint's family; after he had died in Sokovia, both twins felt obliged to help them. They knew loss better than anyone; losing their parents, then all of their friends, then their family, then a part of themselves, and then their home.
Wanda had also been close to Sam- he was practically an older brother to the twins.
Then there was Vision. Wanda loved him with all her heart and he practically felt her break after he died. He felt only a tiny portion of the pain ripping through her body, and even that was unbearable.
So after everything- after killing Thanos, after coming back- Wanda had given up. The twins lived in a fairly nice apartment near enough to the Compound that Pietro could go help out there, but not close enough for Wanda to know.
For the first couple of years, Pietro would find Wanda on the bathroom floor, sobbing and bleeding. He had tried to get her help, but every single therapist had fled from her story.
She tried to kill herself once. Pietro never forgot the day he found her barely alive. He never forgot the pain he felt when he thought she was dead.
The last three years had been bad, but she was getting better. She managed to get herself out of bed, get dressed, eat, every day.
She still wasnt quite happy, but Pietro knew this would take time.
When Natasha knocked in the door, telling them they may have a way, Pietro glanced to his sister, who was sitting on the sofa bathed in blankets. He had said he would come.
When he told Wanda, her smile- the one he hadn't seen it five years- told him everything. She was coming too.
Pietro knew what Wanda wanted. He knew that she wanted nothing more than to bring back everyone else. He knew that she wouldn't be happy, but that didn't matter. Because everyone else would be.
And she would have Sam back, and the Bartons, and would bring back Tony's kid- he had told them stories when the two had visited his farm.
He knew she was happy to be able to do this. To help those who could be helped. To fix others even when she, herself, was so broken.