Purity Spike is an ancient elven weapon for the forces of Law. This falcata style blade has a unicorn horn as its hilt and forming the spine of the sword. The mithril edge is magically fused to the horn and is always clean.

Purity Spike
+1 to hit and damage against anything with a Chaotic alignment
Provides a +1 to all saving throws against the effects of Chaotic creatures
The sword does not function and feels uncomfortable for Chaotic users
if the sword is used to attack a Lawful opponent then the sword loses all powers for 24 hours

(I can’t draw worth a crap)