Fiend

A fiend is an evil creature from one of the Fiendish Planes, also called the Nine Hells or the Abyss. They are not just evil, but born of evil; primal malevolence is one of the roots of their nature, and the evil essence of the fiendish planes permeates every part of their bodies. Fiends live long, and some have an inhuman view on time and life. They are capable of viewing a century passing by as inconsequential. The demons and the devils held an eternal enmity for one another as they waged the Blood War. Every creature has a true name that made it possible for other creatures who knew it to gain control over the them. For fiends, the true name was a double-edged sword. Knowing their own true name made it possible for a fiend to rise up the fiendish ranks, something that was very difficult for fiends without that knowledge. On the other hand if knowledge of a fiend's true name somehow spilled out, it granted other creatures control over them. This control extended very far. For example, a mortal knowing the true name of a fiend could not only call it from the Lower planes to the Prime Material plane but also force it into servitude. Fiends could inconvenience or torment their rivals by helping mortals discover their rival's true names. As mentioned above, a fiend needed knowledge about its true name to rise up the fiendish hierarchy. It often happened that the true name became different on changing form. It was believed that this was not the true name changing but some form of evolution of the true name. The core of the true name remained the same but there were some additions to it. When a mortal used an outdated true name to bind a fiend, the fiend responded to the binding. However, the control the mortal exhibited over the fiend was not complete and could have fatal consequences for the mortal. Mortals and the worlds they inhabited were often seen as useful by fiends, though this did not mean that they viewed mortals as having any intrinsic value. The value of mortals laid in their potential to be turned into fiends after dying. To do this, mortals were exposed to temptation by certain types of fiends. Otherwise, mortals were of use only as slaves, playthings, food, and mercenaries as far as the fiends were concerned. The Prime Material plane was seen as a potential battlefield due to its lack of guardian outsiders, however, it was at its most useful when used as a generator of faith. The most important event in the history of fiends was the Blood War. The Blood War was an inter-planar battle between demons and devils, which cost many lives. Thus, both sides were forced to figure out how to rapidly refill their ranks. The answer both sides came up with was to utilize larvae, which souls of evil mortals would become upon death. As larvae would turn into fiends, these fiends could be used to bolster the ranks of either army. Because of this, both demons and devils started to work towards turning mortals evil. The life expectancy of a fiend was not known. An observation about their aging process was that they did not mature. Those fiends that reproduced, gave birth to a smaller version of their species that grew bigger and stronger with time, but a fiend dying of natural causes or just growing old was never observed. Because of this, it was assumed that they were immortal. One unique feature was that they changed from time to time into a different form. However, this was transformation and not some form of biological metamorphosis.