weiß kreuz fanfiction

[Guest really-desperate]

Hello, I'm searching for a fanfic I've been looking for for days. I can't remember the name (sadly), but i know it was also on archiveofourown as well as here. the author only had one weiß-kreuz fanfiction.
It was about Aya capturing and torturing Schuldig for information about his sister's whereabouts. It's really one of the best pieces of fanfiction I've ever read and i would be devasted if i couldn't find it anymore, so please, please help me!