So, while watching feom the penaltybox, I noticed something strange In my rep. I know what happened, but
Can I find the list of deleted users somewhere? Because I want to know, what happened to that person with a total 12 upvotes in my questions.
No, you can't find out. Votes are private, so revealing who was the source of your reputation changes from vote reversals would violate that. In addition, users are allowed to leave quietly if they want, or if SE removes them for violating the terms of service.