An assassin is a spy who has developed the skills required to eliminate the enemy, while spies can poison or injure they do not seek to kill as that often raises alarms quicker and justice for the kill puts them in danger. The few spies that take the step are ruthless killers, devoid of morales, able to kill with whatever means they can employ to do so unseen and most importantly without leaving evidence of who did it, capable without poisons and explosives.
Assassins will kill indiscriminate to get to their target or to escape, they will destroy buildings just to eliminate one person, sink a ship to prevent being followed, even leave a settlement defenceless if it's the only way to leave. Skilled with all small weapons, throwing weapons, most poisons and toxins, explosives and incendiaries, and with a working knowledge of structural engineering.
