To screencap a long manhwa, you could try using third-party screenshot apps if the default methods don't work well for you. Just make sure to download them from a trusted source. Another option is to scroll through the manhwa section by section and take multiple screenshots to capture the entire length.
One way is to split the long manhwa into sections and take multiple screenshots. Then stitch them together using image editing software. It might take a bit of time but works well.
I think 'Solo Leveling' has a great story. The concept of a weak hunter becoming the strongest is very appealing. The story is full of action - packed battles and the protagonist's growth journey is really inspiring. There are also various mysteries and political elements in the manhwa's world that add depth to the overall story.