I came up with a self-defense tool that debuted at Blade Show this summer: the ST-1. They're waterjet cut from 1/4" 4140, ground and heat treated, with a Cerakote ceramic gun coating, with Boltaron sheaths.
There's no blade, but the tip is quite pointy and beveled.
A closer look at the tip prior to heat treatment and Cerakote.
More details in this video:
As Tobin demonstrates, they can even be quad-wielded. :D