What makes an NPC distinctive? The personality traits, stat blocks help describe an NPC, but I feel that it is the background that truly defines him/her/it and gives root to the dreams, ambitions that it has.
(The honest truth, this only applies to making the NPC distinctive to the GM. It is the party's interactions with the NPC that truly make it distinctive. So as the old adage goes: "If a tree falls in the forest and the PC are not around to hear it, did it really fall?" The answer, “Only if the plot requires it to have fallen”).
To this end I have decided to create a World setting to house the Fantasy NPCs: It is a conventional world that uses standard 3.5 rules, and, from a day to day point of view looks typical. It is, however epic in scope and history.
Here is the Outline
Dawn of Awareness
"Hot Ground, Bright Sky" this was the first moment of awareness was experienced by a living thing on the first world. It was prototypical green slime, and it was experienced a moment before it was torn asunder. Three of the surviving fragments recalled the thought and continued it. One found it's self thinking of the future and became “Dream", another started to take action and began to change the world around it's self and became "Change". The third witnessed this and remembered it for ever, and in doing so became "History".
Of the other fragments, History doesn't speak of them, though it is postulated that they went on to become every living thing.
"History" tells us that, before it was history, it was mealy The Watcher and thus unable to recount the actions of others in it's current and detached manner, for the first million years or so.
"Change" had a vast impact upon the world during those years, building mountains a grain of sand at a time. Change affected and encouraged the conquest of the lands by plants. Change altered some and they began to eat.
"Dream" conjured a vision and made it manifest in the world, it was a simple thing by today’s practice of the arcane but it was still the first magic to have ever been used. "Change" learned of this and begin to use magic too.
Plants spread across the lonely land, Change brought some of them to awareness, and was horrified as they warred with each other. In time they learn of Magic and The land burned with freezing electrical arcs, seas boiled and when it was done History tells us that it would be a million years before the plants would return to the glassed soil.
"Dream" conjured a concept, that Change made manifest in the eaters, and the remaining plants, it was compassion for kin and others.
Of the eaters, Change, did spread them across the land, and they kept the plants in check. With time Change encouraged some of the eaters to eat other eaters.
History says that though stability was achieved for a time, the system fell out of balance and Change altered other eaters and producers time and again to attempt to bring they system back into balance.
"Dream" suggested that it was time to try again with awareness, and Change made it so.
History tells us that the world saw shining wonders during that million year golden age, of which a few remain, and nightmarish tragedies, a few of which also remain in the world. Its end was not brought about by their own actions but by the cruel fate of the universe: A new star shown and the sky burned for weeks.
"Dream", realized that the universe was larger than the world and set about exploring it. History also turned toward the sky.
Change was left alone on the world, ignored by history, and unguided by Dream. It attempted to recover the world, trying to help the survivors, and encouraging new forms of life in the world. It was during this unremembered time that change brought some of the worst mistakes into the world.
Then the world froze. Change tried to adapt the living to this frozen planet, and found it too difficult, so he adapted the numerous dead.
As suddenly as the snow started to fall it burned. Change struggled to keep the balance. He infused creatures to make them more adaptable to the constant alterations of the environment, and at some point it failed to include compassion in the mix.
History, having completed its studies of the sky, brought it's attention back to the world and found the wreck of the world. It encouraged change to impart some order to the creatures that dominated world. Change, hungry for guidance, tried, but without Dream as guidance, did not succeed in returning the world to the golden age of times past.
After a time, the Dream returned, and was horrified at the world, it was also terrified, for it knew the ultimate fate of the world. Dream encouraged Change to temper its actions while Dream slipped into fitful, thoughtful nightmare slumber.
When Dream awoke, some semblance of stability had returned to the world. To it's kin, it described the Ultimate Fate of the world, and described a plan by which, all that they had helped could be preserved, and that the contention for territory between all the different creatures for territory might be alleviated, if not forever, then, at least for a very long time.
History stayed to watch, while Dream drafted legions of the living and the dead to help preserve the world. Change left to build the sunless world.
The sunless world was partially completed a billion years ago, and every few millennia Change removes a substantial population of the world to sunless for preservation.
Dream, has been busy moving one of the larger worlds, messenger as humans of this world call it currently, into to position to guide the world farther away from the bloating sun.
This is the world that the Fantasy NPC inhabits. Ants in a jar, neglected by compassionate ascendant entities who are to busy saving the world to pay attention to it.