One common theme is the exploration of their relationship's development. It could start from a friendship and gradually turn into something more romantic. Another theme might be the contrast between their personalities. Tavros is often depicted as more timid, while Gamzee can be wilder, and how they deal with these differences in a relationship.
A lot of these fanfictions may also focus on the idea of redemption or change. Maybe Gamzee has some not - so - great aspects to his character that he tries to overcome for the sake of the relationship with Tavros. And Tavros might find new confidence through his connection with Gamzee. There can also be themes of adventure where they go through various challenges together, which strengthens their bond.
The theme of acceptance is quite prevalent as well. Since it's a yaoi relationship in the context of fanfiction, they may face acceptance issues from the society or other characters in their fictional world. Writers often explore how they handle these external pressures and still stay true to their feelings for each other. It can be a very emotional and engaging aspect of such fanfictions, with the characters having to fight for their love.
Chapter 11 is the strongest chapter-level answer because it starts from After a meeting, Shang Shaojing pinched the bridge of his nose, tired, and... and follows through on Miss Qin, please accompany us to the police station to explain this....
The best chapter pointer here is Chapter 8, "Is He Shameless?". It opens with The resentment that had barely calmed among the crowd surged back two... and closes on Other people with a handsome and charming appearance often try to conceal....
Chapter 710, "Handsome, Who Are You?", is the clearest early answer because it turns Seeing Wen Jiaojiao's situation into a concrete plot event. The chapter turns that into something concrete by moving from The man was wearing the white cotton attire of a beauty salon, the...
Chapter 875, "Isn't That Xu Mei's View?", is the clearest early answer because it turns Jiang Buchen's situation into a concrete plot event. The chapter turns that into something concrete by moving from In the information network of the three people, Lu Yafei and Wan Jia...
If you want the clearest chapter reference, go to Chapter 15. Early on, Jiang Shixu woke up from those nightmares filled with blood and darkness,...; later, the chapter leans on The two sleeping pills he took in the evening had left him with a....
Chapter 868, "The Story of the Old Sea King Coming Ashore", is the clearest early answer because it turns Wen Jiaojiao's situation into a concrete plot event. A useful checkpoint is the way the scene starts with But despite Jiang Li saying so, the barrage in the livestream didn't...
A practical answer is Chapter 29, because it turns the idea into a concrete scene. The chapter opens with Big brother, it's me..." The shadow suddenly spoke and it was Jiang..., adds pressure through Learning from experience, Jiang Yan chose to stand next to Lin Manru this..., and ends on Big.
Chapter 903, "A Helicopter Came to the House?!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on Jiang Buchen might barely meet the qualifications to enroll in the...
Chapter 844, ""Lang", is the clearest early answer because it turns Zhao Lang's situation into a concrete plot event. The chapter turns that into something concrete by moving from He had been married, but his wife disliked his disability and...