i think you mean the Kulshedra whip, you unlock it by collecting all LP pieces on story mode, i don't remember where, but there's plenty of tutorials on youtube, but, if you mean those weapons (Sai Fung), you unlock them by completing 100 chapters on any difficulty above medium, and the outfit you get it at rodin's hell gates store by purchasing first a "super mirror", it will then unlock all the outfits on the store, every outfit cost 100,000 halos