The story is a crossover with a video game. Here's a clue: I Have Dedicated My Life To The Study Of The Deadly Arts. I Can Blend In With Any Crowd. Strike From Any Direction. And Eliminate Anyone With A Single Thrust Of My Blade. My Name Is A Mask That I Can Hide Behind And My Actions Will Be Remembered For Ages To Come.

If you can guess it right then you can suggest things for the story. If you think you have the right answer post it in the comments.