One popular crossover is with the Cowboy Bebop universe. The gritty, space - western settings of both series blend well. Another is with the Berserk universe, as the dark and violent themes can create interesting stories when combined with Wolfwood's character. And there's also crossovers with the Evangelion series, where the complex psychological aspects of Evangelion can be explored along with Wolfwood's own internal struggles.
You can start by looking on fanfiction platforms like Archive of Our Own (AO3). It has a vast collection of fanfics, and you can use the search function to specifically look for Nicholas D Wolfwood crossover stories. Another option is FanFiction.net, though the tagging system there might be a bit different.
Overall, Trigun Stampede adheres closely to the manga. Some minor details might differ for the sake of the adaptation's flow and visual presentation, but the core remains the same.
The Trigun manga has a considerable length. It consists of multiple volumes and chapters, but the exact number can vary depending on the specific edition and printing.
One common theme is the exploration of their complex relationship. Given their different personalities and backgrounds in the original work, fanfictions often delve deeper into how they understand and support each other. Another theme is adventure. They might go on new quests or face new threats together, building on the action - packed nature of the original story.