The Shadow of the Underground (Attack On Titan X Skilled! F!Reader)

[Under Major Editing, and Being Continued :)] Shadow. That's what you've become known as over the years that you've lived in the Underground. You've done what you needed to, to survive- from theft to murder. You're not proud of it, but you don't regret it, either. Luckily, you haven't been alone the entire time. Your...