Well, in addition to Wirt and Greg, there are also other important characters. There's Beatrice, who becomes an ally to the brothers on their journey. She has her own backstory and motives that are intertwined with the boys' adventure. Then there are various strange creatures they encounter along the way, like the Woodsman, who also play significant roles in the overall story.
Another interesting angle is to focus on the side characters. You could write a fanfiction about the Woodsman's past. What was his life like before he got trapped in the never - ending task of keeping the lantern lit? It could be a tragic love story or something related to his family.
One interesting aspect is the story's setting. It creates a sort of otherworldly, autumnal atmosphere that is both nostalgic and mysterious. The use of different locations within this over - all world, like the Dark Lantern Hallow, adds to the sense of adventure and discovery. It's like every page is a new exploration.
Begin with creating an outline. Decide on the starting point, the middle events, and how you want it to end. If you're writing about a new adventure for the brothers, list out the different obstacles they'll face. For example, new strange creatures or mysterious places. And don't be afraid to add your own unique twists to the story.
There are many interesting fanfictions that combine these three universes. Some might focus on characters from each series meeting in a crossover adventure. For example, Harry Potter characters could find themselves in the strange and magical world of Gravity Falls, or in the eerie yet enchanting world of Over the Garden Wall. The possibilities are endless for exploring different character dynamics and plotlines.
I'm not sure specifically as I haven't read it. But generally, a graphic novel could be about various things like adventure, relationships, or a unique fictional world. It might tell a story of characters trying to overcome some kind of obstacle, which could be related to the 'over the wall' part, perhaps a physical or metaphorical wall.
I don't know who the main characters are as I haven't read it. But they could be ordinary people turned heroes, like a young boy or girl with a strong will.