The middle, if it has three scars, that means harm. And the holder will meet an accident in his life.
9 seconds sound clip from the Ninja Swords of Death movie soundboard.
You can hear this line at 01:16:30 in the DVD version of the movie.
Quote context
[...]
- If you don't mind me, when I first saw the sword, I could feel the devil's power in it.
- All swords can be classified in several ways. The very first part, let's start from the marks on it.
- You have no way to choose but to die if the sword has one. That scar is most harmful.
- It's a devil's wish. No one can prevent it. You must beware.
[...]