I don’t know if this is the proper subreddit to do this on, but the fic was about Harley Quinn from Batman having the powers of a god and using said powers to make superheroines into her sex slaves, I have seen similar stories, but this particular fic was rather long
Source: reddit.com/r/eroticliterature/comments/asi0u1/need_help_finding_a_fanfic_i_read_a_while_ago