The Allfire, or Archfire in SpellForce 2, is the very essence of Eo's magic and a power only the Godfather Aonir can tame.
As the essence of all magic, every mage that reaches a certain degree of power can perceive its voice. It tells of power, conquests, treasures, glory ... things all men long for. But Allfire is dangerous not only because no one can truly control it, but also because it works the same way a drug does. Once you tasted it, you're forever addicted to it. You always need more of it, more power, more treasure, more glory ... you just can't get enough. And because Allfire is the essence of all magic, it makes a mage's power grow amazingly.
Only three things can kill a being that controls Allfire : another one controlling Allfire, a God or the flames of a Great Dragon. That's why mages controlling the Allfire are so hard to kill ... but they still can be killed
Allfire is related to the Fall of the Shapers, the first inhabitants of Eo and children of the gods. After exploring every single part of the world, the Shapers turned to the invisible side of it and found the Allfire. However, even thought the Shapers were powerful, only Aonir could control the Allfire. They became addicted to it and their great civilization became a decadent one. They waged war against each other, always longing for more of the power the Allfire would give them and, eventually, the Great Dragons of Eo awakened and completely destroyed the Shapers' culture, purging the world from their corruption. Only few of the race remained who were the ancestors of the elves, dwarves and humans.
Thousands of years later, the mages of the Circle wanted to use the Allfire to do good in Eo, but they fell under its power the same way the Shapers did. And their desire for the power of the Convocation didn't help it. After the last mage of the Circle died, the portals of Rohen started to loose their power, meaning their power source was most likely Rohen's control over the Allfire, but this fact has yet to be confirmed.