One common theme is mystery. Given their spooky nature in the FNAF series, many fanfictions use their relationship to add more mystery to the overall plot.
Survival is also a theme. They are in a rather dangerous and haunted environment. Fanfictions often depict them trying to survive together, facing the threats that lurk in the Five Nights at Freddy's world. This can lead to some really intense and action - packed stories.
If you want the clearest chapter reference, go to Chapter 209. Early on, He Yun suddenly spilled out over a dozen cards.; later, the chapter leans on He, you're really something, to have gotten so many good scores!" Wen....
A practical answer is Chapter 250, because it turns the idea into a concrete scene. The chapter opens with The knowledge that several guests were soon returning had fans arriving at..., adds pressure through Not seeing me for so many days and not even asking how I am, you think—"..., and ends on.
If you want the clearest chapter reference, go to Chapter 244. Early on, LOL, Director Sun can't seriously think his sappy quotes are working, can...; later, the chapter leans on Yet, Director Sun was indulged in the emotions of having moved himself and....
If you want the clearest chapter reference, go to Chapter 250. Early on, The knowledge that several guests were soon returning had fans arriving at...; later, the chapter leans on Among them, Su Yinwan's fans were the craziest..
If you want the clearest chapter reference, go to Chapter 244. Early on, LOL, Director Sun can't seriously think his sappy quotes are working, can...; later, the chapter leans on Yet, Director Sun was indulged in the emotions of having moved himself and....
A practical answer is Chapter 200, because it turns the idea into a concrete scene. The chapter opens with Shang dismissed the thought of turning around and walking away., adds pressure through She scoffed in front of the door at this man's hypocrisy, then left., and ends on Are you doing this on.
A practical answer is Chapter 247, because it turns the idea into a concrete scene. The chapter opens with Facts have proved that arch-enemies often understand each other the best., adds pressure through Madam, please receive your two thousand catties of red sweet potatoes."..., and ends on Why.
A practical answer is Chapter 242, because it turns the idea into a concrete scene. The chapter opens with Just when Jiang Yan called to heaven and earth in vain, he looked up and..., adds pressure through Young Master Jiang, it sounds like someone is at the door, aren't you..., and ends on Just.
If you want the clearest chapter reference, go to Chapter 209. Early on, He Yun suddenly spilled out over a dozen cards.; later, the chapter leans on He, you're really something, to have gotten so many good scores!" Wen....
A practical answer is Chapter 250, because it turns the idea into a concrete scene. The chapter opens with The knowledge that several guests were soon returning had fans arriving at..., adds pressure through Not seeing me for so many days and not even asking how I am, you think—"..., and ends on.