One of the well - known martial arts novels could be 'Crouching Tiger, Hidden Dragon'. It has elements of martial arts and a touch of Eastern philosophy. However, I'm not sure if it exactly meets the 'echi' part which might be a misspelling. Maybe you mean 'epic'. If so, 'The Legend of Condor Heroes' is also a great one. It's full of exciting martial arts battles and complex characters.
I'm not familiar with the term 'echi' in this context. But 'A Record of Mortal's Cultivation to Immortality' has some martial - arts - like elements. The protagonist has to train hard and fight against various enemies, with detailed descriptions of his growth in power. It's a popular novel in the cultivation genre which is related to martial arts in some ways.
Echii mangas usually have more adult-oriented content like sexual themes and imagery compared to regular mangas which may focus on a wider range of genres and themes.
Hentai lolis mangas typically contain inappropriate and potentially illegal content involving underage characters in sexual situations, while regular mangas focus on various genres and themes without such explicit and objectionable content.
Yes, mangas can be considered graphic novels. They share many characteristics such as being a combination of text and illustrations to tell a story. Manga typically has its own unique art styles and narrative structures, but like graphic novels, it uses sequential art to convey a plot, develop characters, and create a fictional world.