A frequent theme in these fanfictions is the OC's hidden talents or abilities. For instance, she might have a special skill in profiling that she's been developing on her own. This theme of self - discovery within the context of the 'Criminal Minds' universe is really engaging. Also, the theme of friendship within the BAU is often explored as the OC sister forms relationships with the other members of the team like Reid or Morgan.
The theme of redemption can also be found in some 'Criminal Minds JJ sister OC fanfiction'. Maybe the OC has a past mistake or something she's ashamed of, and through her work with the BAU, she gets a chance to make up for it. It adds an extra layer of depth to her character and the overall story. And of course, the overarching theme of solving crimes and bringing justice to the victims is always there as it is in the original 'Criminal Minds' show.
Chapter 868, "The Story of the Old Sea King Coming Ashore", is the clearest early answer because it turns Wealth Seal's situation into a concrete plot event. It opens with But despite Jiang Li saying so, the barrage in the livestream didn't... and closes on I came early;
Chapter 730, "How Can You Make a Deal with a Madman?!", is the clearest early answer because it turns Xu Ning's situation into a concrete plot event.
Chapter 37 is the strongest chapter-level answer because it starts from The barrage was suddenly filled with hahas, but the two guests present... and follows through on I look forward to your guidance." He Yun nodded slightly, then continued....
Chapter 832, "So Impressive, My Sister!", is the clearest early answer because it turns Yu Fei's situation into a concrete plot event.
Chapter 833, "She’s Also a Quick Transmigrator?!", is the clearest early answer because it turns Sister Li's situation into a concrete plot event.
Chapter 910, "This place isn’t fun, I want to go home!", is the clearest early answer because it turns Jiang Buchen's situation into a concrete plot event. Early on, Jiang Bufan was not very shy.. By the end, It's all sister's fault for bringing us here..
Chapter 878, "Do You Dare?", is the clearest early answer because it turns Xiao Ni's situation into a concrete plot event. The setup is Su Yinwan not only chose a remote location for the meeting, but the..., but the pressure keeps building through The meeting was set for eight in the evening..
Chapter 21 is the strongest chapter-level answer because it starts from Jiang Li's clear and logical explanation had everyone stunned in place. and follows through on But the implications could be different..
Chapter 789, "Son Toad", is the clearest early answer because it turns Shang Shaojing's situation into a concrete plot event.
Chapter 23 is the strongest chapter-level answer because it starts from Although Jiang Li exerted very little strength, Jiang Yan instantly felt... and follows through on However, just as she buried herself in the study, pouring over mysticism....