Humans come from the world of Lagena which is the sister world of Ilysia. Both of these worlds have lesser and elder gods, lesser gods are found everywhere.
Lesser gods can be found in the world and in dungeons and interact with it. Each god will have different experiences and can be fought. They can be massive and very intimidating.
Everything Humans do is based on forcing magic and life force from the gods and from the planet to bend it to their needs. Humans have learned how to twist magic and create machinery.
The Humans have sucked all the mana from their planet and killed their gods, still wanting more they opened a portal to Ilysia.
The world of Ilysia in inhabited by many races, 2 of which are the elves and orcs and the humans have come waging a massive war, to do this the portal needs to be opened to a massive scale. The Humans do this by slaughtering a god over the existing portal.
Once in Ilysia the first the humans do is lay waste to the forest they came into and started building siege engines. The Humans bought their gods with them. They use the siege engines and gods to go to war.
The humans cause death and destruction in a huge war but are eventually pushed back by the Ilysians who close the portal locking some humans in Ilysia and pushing the rest back to Lagena.
Most of the humans are captured in an enclosure but some avoid that fate and continue to ravage the world of Ilysia with their war machines.
Some 600 years later the barrier around the human enclosure is finally lowered letting them out to be trusted to clean the corruptions of the world and destroying the war machines that are the result of the humans still ravaging the world.
The game Ilysia is about the redemption of the human race.