To give some Kasumi explanation: Kasumi is Cassandra Cain's cover identity when she was on the Justice League Elite team. During that time she had two katana and even picked up a thanagarian Shadow belt (just like Shadowthief) which she used to pretend to be a metahuman when undercover, giving her the ability to travel through shadows and go intangible, when not in bright light.
However, I don't think katana are sufficient to hurt Timber Wolf.