http://www.brokentier.com/blogs/news/14946957-under-night-in-birth-simple-character-guide
Watch the videos on yuzu part, it helped me understand her a lot but shes going to take time.
also this as well. http://wiki.mizuumi.net/w/Under_Night_In-Birth/Yuzuriha http://in-birth.wikia.com/wiki/Yuzuriha_(Gameplay)
hope it helped :D