Heralds of Shokaract

They are the half-god's most important asset next to the Matrix of Conquest. Intelligent, ruthless, powerful, fearless, and above all, unwaveringly loyal, the Heralds strive to maintain Shokaract's rule over Cybertron and eventually to expand his domain over the whole universe. The highest in command of them is the Herald Maximo, who only has to bow for Shokaract himself. Because of their importance, the selection procedure for new Heralds is rigorous. First, one has to prove oneself worthy of the Ko-tu ritual, the final test to become a Herald, through exemplary achievements in battle. Second, one has to pass the test within the Ko-tu ritual: killing a prime enemy of Shokaract, a Herald-to-be's so-called "alpha target". Failure is met with a slow and painful death. Success, on the other hand, means ascension to the ranks of the Heralds, which comes with the implantation of a device that destroys the Herald's mind if ever they'd come to betray Shokaract.

Reference: https://tfwiki.net/wiki/Herald_of_Shokaract