Nen is about the same as Samurai Arts, except Samurai Arts is more showy and flashy which is why I prefer it. It would be basically a literally fight of "Anything you can do I can do too just in a slightly different style and way" 

I am not saying it would be an easy battle for Kiyu, and if Ethereal joined in he'd probably lose without back up. One on one which would what Kiyu would challenge her to would be a completely different story.