A cult of assassins, the Spirit Blades are dedicated to their art. As an organization, they hold high the principal that nothing is more sacred than life. The most fit to rule are those who live – the longer the life, the harder the trials, the more worthy to command.
As such, the Spirit Blades devote their time and resources to two ends. The first is to constantly test those in power, to see if they are deserving of it. The second is to prolong their own lives and hence exert power over others.