At first, there were humans.
The actual amount of knowledge and history on early humans is slim. They built, they fought and they survived. Nobody knows where they came from. Some say the sea, some say the sky and some say the stars and beyond. It's funny though, regardless of this, humanity still ended up liars. They were never first.
At first, there were monsters.
Of all shapes and sizes. What small documentation exists of early Humans always mention back to Monsters. They tore through what meager settlements Humanity could set up. They shifted mountains, flooded oceans and cracked the ground and sky. This substantial interruption to their ecosystem was not welcome.
Next came they Slayers.
Humanity sound found itself in a dire situation. Adapt or perish. Humanity chose the former, and thus the Slayers were created. Humanities strongest banded together to fight the Monsters, using swords, spears and bows to carve out a home for Humans in the harsh world it had been placed into.
Piece by piece, the Slayers made humans a home. Villages became towns, which turned into cities. Few of which went on to become bastions. Huge fortress cities built to withstand the strongest Monsters could throw at them at the time. Humanity secured itself in this unforgiving world, all thanks to the monolithic feats of man preformed by the Slayers.
The Monsters of course, responded in Kind. They evolved to not only combat the threat Humans posed to their habitats, but the constant threat of other predators. They grew stronger, more ferocious. New sub-species were documented and new species entirely emerged from the depths of the earth and lands unknown.
Humans and Monsters are now locked in an ever changing battle, humans, wishing to find a home in a world that rejected them from the beginning, to thrive and understand the things around them, and Monsters. Ever evolving to fight both themselves and Humanity.
These days, it's the dream of thousands to rise up and become Slayers. To explore the vast unknowns of the world, and fight what divine creatures may reside there and come back a legend. Slayers operate in most Human settlements, from the largest Bastion to the smallest village. It's in one of these villages where we meet Gram, and follow him on his journey to become a legend, and carve his own path in the history of Man.