The Lore of Blazes

The Blaze is known to be one of the strongest creatures in the Nether. Unlike other creatures in the Nether, it is not an original inhabitant. The Blazes evolved from the ancient species of Men, the prior form of Endermen. Before the Endermen were hauled into the deep confines of the Ender, they had discovered the broken heart of the Block: the Nether. [Compiled History of the Nether Pg. 4 for Reference].
The Men had gotten tired of the Overworld, so they decided to explore the strange substance they had found under the Bottom Rock (later named Bedrock). As they collected this material called Void, the sent it to their magicians and Spellcasters. Using ancient Phaeric (Archaic Overworld Language - Lost in the seventeenth millennium) they unveiled that the Void was not devoid of space and time. The truth was that the Void was a collection of parallel Universes and Spirit Worlds.
The Spellcasters worked on a way to open these worlds before they discovered that by changing the essence of obsidian they could alter the chemical reactions that fire produced on it. In essence they changed Obsidian so that when touched by fire, the Obsidian would open a portal to the Nether.
The Men decided that someone should be sent to explore the Nether, so the first team of "Conquerors" entered. Their so-called mission was to explore the Nether and map it out.
The Men returned two weeks later, many missing and some irreparably changed. It was Tuafor the Third, son of Uendir that spoke of the Nether.
"The fire burns bright, night and day seem to dissipate for there is no sky, just floors o carnage and lava. There are entire areas covered with thick sand, the souls of the dead inhabit in it. Huge ghouls roam around, floating and shooting spewing balls of fiery evil out of their putrid mouths."
Although for most of the Men this sounded horrible and inhospitable, there were those attracted by evil and danger who ventured forward. These formed small colonies built from baked Soulsand baked into bricks. They stretched miles and twisted like the minds of its inhabitants.
The Overworld Men either forgot them or chose to shun them. It was so that when the Nether-Livers returned with twisted pig men that the Overworld Men chose to seal them in in the nether, choosing to close the portals with all them inside. The Nether-Men became bitter and made armies of "Pig Men", for they would find a way to activate the portals and come back.
For entire Millennia they looked for a solution. They became bitter and crouched low, stooping and consuming themselves in their own hate. Through processes unknown, the Nether accepted them, choosing not to attack hem, but change them into fiery horrors, a metaphor for their hate.
It was many thousands of years after, when the Men forgot about them, that they attempted once again to explore the Nether. When they entered they met the ancient Men, still recognizable in their blackness. It is so that the Men tried to close the portals, but they were again trapped inside. Fortunatly, thy sent a distress signal to the outside, were the Overworldians were horrified.
The Spellcasters tried to change the Blazes back, but this proved to be their Demise.