Source: Cheliax, The Infernal Empire, pg(s). 60
Fiend-infused golems are golems animated by an imprisoned evil outsider instead of an elemental spirit like normal golems. Unlike normal golems, fiend-infused golems have a brutish intellect and a desire to destroy good. The rage of the fiend subjugated inside the golem increases the risk of the golem going out of control and manifests as ever-burning hellfire; as a result, fiend-infused golems can never be made from flammable materials. The first fiend-infused golems were created by artisans in the Jistkan city of Rachikan, who mitigated the risk of the bound fiend going berserk by infusing them within the enormous behemoth golems. In modern times, many fiend-infused golems still guard Jistkan ruins, and their secrets have become known to contemporary artificers; those of House Thrune are particularly interested in them.