Fiends are the race of lifeforms that the Purists were at war with a millinea of years ago.
Fiend Civil War
On their homeworld, by the time their Empire had become one unified conglomerate, The Fiends experienced Rebels. The Planet was torn apart between The Imperials, and The Revolutionists. The Revolutionists triumphed, and the Fiend race was ruled by High Clans lead by Fiend Patriarchs. They then set out to colonise other worlds.
Fiend - Purist War
Several years later, The Fiends encountered The Purists. They battled for several years, as The Purists struggled to defend their home system. No matter how hard The Purists battled, they still, in the end, lost. The Fiends siezed their home system for their own and began colonization efforts. For the next several thousand years they continued to expand, until, eventually, they were discovered by a race known as The Oracles.
Induction into The Zodiac
The Oracles introduced the Fiends into The Zodiac, seeing them as a fit race for Military pogress. Everything was fine... until. The Purists and The Fiends had met up after so long, and things began to fall apart. During the Battle of Earth, The Purists seperated from The Zodiac, as did the races that greatly respect them, and so began a great divide.
The Great Divide
The Fiends, now in charge of the Military, enslaved all of the new races. The Scamps, Destroyers, Hydra, and Scarabs, all fell under Fiend rule, not even The Oracles liked this, but they got the job done. By the end of The Great War The Zodiac began to reform.
By the end of everything, The Purists and The Fiends, and thus, all the races in the Zodiac, became allied, and eventually, friends. It appeared as though peace had finally been realised. The Fiends, would indeed, go down in Zodiac history, as one of the most ruthless races to ever set foot in their council chambers.