Fiends are entities of darkness and evil. These entities are of a complex Order of Being.
The Blood Magic tradition provides for a means to enable a Blood Oath between a Fiendish entity and Divine Principle to support a Compact of Dark Shelter. The cementing of the compact is always done through a offering of Blood and Souls. The breaking of the compact triggers a violent and harsh Transgression.
Animating Force: This type of creature can supply an force imbued in Technological items to operate them. Energy/power is either through a discipline of Technomancy or often from a mystic living source; Animation using an Elemental, Fiend, or Celestial bound to an item to motivate it, or simply as a fuel source. The former gives more flexibility, limited by the ability to command it. The later is typically canned reactions and output which can be manipulated by anyone with the knowledge of the item. Constructs and Golems can also be powered through approaches of Technomancy.