Not my brother by blood (s.r X reader)

!!READ THE WHOLE DESCRIPTION!!
You're a former assassin that was captured by HYDRA, there you met a man you grew attached to, as a big brother, a person that protected you from everything. Now the avengers are currently in the possession of your big brother and you brought friends to kinda, free him? No, well you're definitely finding him first.
The reader is also kinda cocky, with a mixture of Deadpool and Tony Stark humor, but she's also very nice

The text written in italic are the Reader's thoughts

I don't own any characters I only own the plot

This is my first fic, ever. I was inspired by the art on the cover, that belongs to http://axeeeee.tumblr.com (if I'm wrong place correct me)