Cyclone blade （Shiranui ） 

This weapon was carried by Kunoichi, who is a character introduced in Samurai Warriors.

Blade Production process: black plated and grey metal baking finish face

Samurai Warriors(Sengoku Musou3 in Japan)is the first title in the series of hack and slash video games,based loosely around the Sengoku ("Warring States") period of Japanese history and it is a spinoff of the Dynasty Warriors series.