Assassians are those that pecialize in killing or disabling their opponents swiftly and silently.  Many groups use asassians from  rogues guilds, to every government ever known to rule on the world.

An assasian has to have studied to be a warrior and a rouge because they must combine the skills of both classes.  once they have reached a mid level in each of theses classes they can then start assasian training.. which specializes in moving in quickly and silently and making single deadly blows..  they are masters at hiding in shadows or even  in plain sight if they can prepare a few moments.  they tend to be masters of many weapons but often have one they specialize in and can weild like few others.

The assassian is a deadly powerful  group of people with a particular skill set that makes them exceedingly deadly.