The 'wingfeather saga graphic novel' probably tells a story full of heroes and villains. It could be about a group of characters on a quest to save their world or discover some great power. It might also have elements of magic and different races of beings, like elves or dwarves perhaps, that interact in a complex and engaging story.
One idea could be exploring the backstory of a minor character in more depth. For example, the innkeeper in one of the Wingfeather Saga towns. What made them settle there? What secrets do they hold? Another could be a 'what if' scenario, like what if the main characters took a different path at a crucial decision point in the story. Maybe if they had allied with a different group instead of the one they did.
The Fangs are often written about as well. They are the villains in the story, but their unique appearance and motives can be really interesting to expand on. Fanfiction could explore how they became the way they are, or even a scenario where one of the Fangs has a change of heart and tries to break away from their evil ways.
The introduction of the 15th episode of The Nameless One was about Qian Zhifeng and Han Caiyi hiding in the woods when the fire was too strong. In this episode, Qi Feng was intercepted by Shimada with the coffin. When the Japanese insisted on opening the coffin, the mechanism inside the coffin was triggered, causing an explosion. Qi Feng smiled amidst the sparks. Other than that, the other plot details were not mentioned.
The plot introduction of the 14th episode of the Nameless One was that Qian Zhifeng accidentally found the note that Xiao Chang gave him, which made him very angry and confronted Han Caiyi. Qian Zhifeng was worried that Joseph would be chased by the Japanese because he was very vigilant and would not be manipulated by others. Xiao Tong's reckless behavior might lead to danger. However, other than that, the plot details were not provided.
The plot introduction of the 20th episode of The Nameless was: Zhao Yuanchu gave Qian Zhifeng a longevity lock, saying that it was for his son. In the chat, he said that he found a safe key in Qiao San's house, but when they went to open it, they found that it was empty. Qian Zhifeng also played dumb and agreed.