it can't just freely cut through any b-rank jutsu and below. in some cases this wouldn't even make sense, like say someone's attacking you with vast water jutsu. that can't just be defeated by swinging a sword. it could create a small defense of some sort at the cost of fair amount of chakra, and would only be able to defend against things that would make sense for it to do so (like the water thing I just mentioned, something like that it wouldn't be able to block). but you can't just cut through any jutsu you want while attacking a person, and especially technique specifically made for defense. also, the user would require a lightning affinity in order to use it