Create a dynamic wallpaper that seamlessly combines iconic superheroes from both DC and Marvel universes. Include characters like Batman, Superman, Wonder Woman, Spider-Man, Iron Man, and Captain America in an action-packed scene. Emphasize vibrant colors, epic poses, and a balanced composition. Ensure that the superheroes complement each other visually and create a sense of unity. Feel free to add a cityscape or other relevant backgrounds to enhance the overall impact