From Tenebrae
Liberators are warriors dedicated to a cause: the freedom from tyranny and the abolishment of slavery. Based primarily in the slave-heavy region of Veyshan, they are notorious for the strength of their belief...and their worship of not a god, but of an ancient and divine relic. Beholden to the very concept of "freedom," the Liberators are barely an order; indeed, they are often seen as a bunch of fruitier than fruitcakes who can't agree on much of anything, let alone what "'freedom' is supposed to look like." They fan out into the world, spreading their order's words to those receptive to it, often taking sparks and embers from the Great Flame, itself. They are often not welcome due to how ardently, frustratingly so, they can champion "freedom," and their internal squabbles over its meaning are the things of legend. It is said that no two liberators can agree on much of anything, and their hierarchy is practically non-existent. While not paladins--they shine, dedicated fervently to a cause idolized by the Great Flame, or Averium, a divine relic of Elhim's great work and intent. However, they're often distrusted--and viewed as nutcases, lunatics, and impulsive. Few people will take them at their word, viewing them as untrustworthy, and some townships may drum them out on discovery.
Averium is not a God. Averium is what Liberators call the Flame of Freedom, set down in the center of what is now the Veyshan Desert. The scholars of the Flame state that it was placed there by the Original Source, Elhim, to remind the Gods of mortal free will. They say that Maugrim the Oppressor then took offense, and that He and Taara then called upon their godly might in ways that sought its extinguishment. Such was the rage of the gods of darkness against this symbol of free will that their efforts created the desert--and the flame burned brightly, still. Veyshan would then grow around it, with the flame mostly forgotten save for those Liberators who know its secrets and guard it. Others argue that it is nothing but a symbol, and one organization within Veyshan holds that it's the remains of a singular, burning genie who had offended the gods of light by inventing slavery.
And yet, another account:
PrC: Liberator - This is the Liberator as republished by Paizo. Staff's been reviewing it (and said archive) for over a year and a half now, and consider it to fit the Liberator's intent better than anything else.