A huge, ancient robot built ten thousand years ago, the Kastelan Robot is a perfect example of the Adeptus Mechanicus’ repurposing of technology. Nearly unstoppable, their only flaw is that of any mere machine; they will follow instructions to the letter, even if this results in their own demise. A specialist Tech-Priest – the Cybernetica Datasmith – must constantly update and reprogram the Kastelan via order dataslates, lest this enormous, clanking robot simply stride blindly into a nearby chasm. Make no mistake, however; when his controls are set to destroy, the Kastelan will destroy.
(Source: Games Workshop)