Well, the themes of Trigun Stampede Original Story include survival. Given the unforgiving environment they are in, characters are always fighting to survive. There's also the theme of friendship. For example, the relationship between Vash and his companions is important. They support each other in different situations. And the theme of good vs. evil is present. Vash represents good, and there are various antagonists that represent different forms of evil in the story.
Vash the Stampede is the central character in Trigun Stampede Original Story. He's known as the 'humanoid typhoon' and is constantly on the run. Meryl Stryfe is a significant character. She's a determined journalist who wants to get the scoop on Vash. And Nicholas D. Wolfwood plays an important role too. He has a unique fighting style and is somewhat of an enigma at first. His relationship with Vash is quite interesting as they often find themselves on the same side despite their differences.
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.
The Trigun anime is known for its resemblance to the manga. It follows the main storyline closely, with only occasional tweaks to make it more visually appealing or fit the animation format. Fans generally appreciate the similarities between the two.