The geographical disaster, ruthless, post-apocalyptic nightmare world of Alseria is a beautiful place not to be in.
A couple of thousand years ago, as a smelly old wizard recorded in his dusty tower basement. Humans were more intelligent than they needed to be, it was a better choice or them to turn to monkeys but they didn't.
A particular human, the smartest of them all said, "Well, we live for 80~100 years. Wouldn't it be cool if we lived forever?"
Humanity replied "Yes, of course, why not? Living forever, what could go wrong? We bet it wouldn't involve any disgusting genetic deformities."
The particular human looked away, "Yeah...I will call it evolution..."
Now, embarked on a valent journey of scientific discovery and the absolute art of perfection. He experimented on humans over and over, funded by his other smelly old dudes sitting at the top of the world.
As expected, the world population reacted to his actions in a meaningful. "That's a noble sacrifice," They said, the idiots.
Technically it wasn't their problem, those smelly old dudes sitting at the top of the world marked the experiments for a better future.
Their genius marketing technic involved saying things like, "If you're sick or dying, how about you offer yourself to our experiments? You can be the first person to become immortal, but the chance is low. And even if you died, the data we collect will help us further the research, and one day, your descendant may become immortal."
Then at some point later, and as expected. The solution they created to make human immortal have been created. {I can't believe they actually did it} But...Apparently, it reacted violently with air, turned into gas, and spread around the whole world in a matter of months.
Now that immortal-making gas has reacted and changed through interacting with the chemical nature of the world, it had some nasty side effects. It could still make people immortal but, it also turns them into horrifying, deformed disgusting monsters.
You might think it ended there but it also affected animals, bugs, and diseases like microbes and viruses.
Now that humans realized the mistake in their actions and discovered that the gas will get dissolved in about two thousand years. Living on the surface or underground was basically impossible.
Instead of crying about like babies and creating propaganda, {Which they did, a lot of them} they asked another really smart person to find a solution. "Go live on mountains' tops!" He said, and they did. But, the monster could climb so they needed another solution.
Then a man came out with an amazingly efficient and productive solution. "Ah, I have this goddess I've been worshipping alone for a couple of years now. She says she will help you if you started worshipping her." Out of options, humans just gave it a shot...not expecting much...
CRACK! Just a few days later, the goddess pulled the mountains from the ground, made them fly upside down, and chained them to the ground.
"She says you can build cities and civilization there, monster won't attack as long as worship her hard enough... and gave the world my name." The man said.
From that day on, he was the first pope and humanity moved to live on the floating islands. And the world was named Alseria, on the goddess's name.
This is really my original script for the world, how it began, and everything—just the basic idea.
I doubt I will change the lore in the future so ask me any question you want and I might added it {If it fits}