/lit/ - Literature

I haven't done any creative writing since I was in highschool 8 years ago. I took a break from actual reading and spent a couple months plowing through as many low quality, Japanese, power fantasy, lightnovels and got inspired to make my own. It was going to heavily parody the genre and I was going to jam as many anime, scifi, and lightnovel references in as I could. Every arc and most of the characters were going to be practically ripped strait from different series which got me thinking. At what point does a work stop being parody and become fan fiction?