There have been whispers of an organization known as the Claw of Shar, however, any details of their existence and abilities known by them are merely rumor. If they do actually exist, this might have something to do with them. Or maybe not. There is no guarantee of the accuracy or validity of anything below.
Choke is an ability believed to be used by the Claw of Shar.
This is a simple but effective choke technique, often frowned upon by people with who believe in "civilized" or "honorable" combat. It requires speed and subtlety of an assassin to catch their mark unawares.