A Tech-Priest is an initiate of the Adeptus Mechanicus, the technological priesthood that worships the Machine God and safeguards humanity's surviving science. To a Tech-Priest, knowledge is holy and machinery is sacred, animated by mysterious spirits that must be appeased with ritual, incense, and precisely spoken litanies before they will function reliably.
As they ascend through their order, Tech-Priests progressively replace their weak flesh with bionic augmentation, regarding the human body as an imperfect vessel to be improved through mechanical enhancement. Elder members may retain little of their original form, their bodies a lattice of cabling, servos, and additional limbs, their voices flattened to a machine drone. This transformation is seen not as loss but as devotion, drawing the adept ever closer to the perfection of the Omnissiah.
Their responsibilities span the maintenance of vital technology, the construction of weapons and war engines, and the jealous guarding of ancient knowledge from a lost golden age. Because the Imperium can no longer readily invent new technology, the Mechanicus instead venerates and reproduces designs handed down across millennia. A Tech-Priest's authority derives from mastery others cannot match, and many worlds depend utterly on their expertise. Secretive, hierarchical, and often unsettling to ordinary citizens, Tech-Priests are indispensable custodians of the machinery that keeps the Imperium alive.