The followers of the mechanogod Whrrrm, those who could never have come about until the advent of steamtech.
And because they had shown they could not be trusted, Iev abolished the use of Kren save by those few individuals he trusted.
~The True History of the Order, by F’ian circa 300 AW
No one is allowed to do harm to those of Highest/ Imperial rank, those of the Imperial household or those related within two steps of blood. The second tradition is an executioner must be of a higher rank than those he executes. This leads to "issues" when someone tries to harm a member of the Imperial clan or when these members are subversive. Such people are often killed by the being chained under a giant bell. They die within a day or so from the vibration, but they die untouched by Human hands.