Trebek, that is a Japanese war knife. It's supposed to be curved like that, even the handle.
This is EPIC. I have never actually seen Hayabusa, just on game, but that is freakin sweet. If you want to be a little different, paint the helmet itself Red, and the forehead stuff that in game is supposed to be white, paint that black. It makes for interesting colour schemes, my friend and I discovered that in MS paint. This is freakin cool dude, please share. Mould it and sell them