The world gets its name from the aurora borealis that can be seen from anywhere. Initially it had one large continent that humans thrived on and actually got fairly advance. High tech cars and building, even getting close to laser weapons. Unfortunately the God of Angels Ikdros starting to see them as a disease.
So to "Cure" this disease his beloved world had he tricked the Goddess of Magic, whom was just coming about from ambient mana having slowly formed, into refusing to help the humans in the interest of her own people. These were the elves.
Ikdros easily convinced her that should the elves come into contact with humans it would lead to terrible things for the elves. And let's be fair. A lot of humans just suck and would do that exact thing.
Unfortunately the few spoil the bunch and Uva believed him so stays away as Ikdros began to warp and twist animals to accomplish his goal. He turned them into monster, having them run rampant and even boosting their resistance to ballistic damage.
They wreaked havoc upon the continent and led to a long and hard war for humans against the monsters. They slowly regained purchase after splitting the continent into three. Two large chucks and an island.
During this time to get the upper hand Ikdros went to the underworld, controlled by Tena, the Goddess of Eternal Rest, and opened a path way from hell and purgatory both. This released numerous fiends, demons, vampires, and other creatures like the wendigo upon the world. Tena was furious and began reaching out to a few select mortals to hunt this creatures and send them back to her. These hunters were knows as ill omen if seen and could be identified by a necklace in the shape of an hourglass with glowing dark green sand.
Unfortunately human greed got the better of them again and they lost that purchase, nearly going extinct. Uva finally realized how bad things had gotten when an Elven city was attacked by the monsters Ikdros created. She stepped in by talking with the leaders of the elves and giving humans sanctuary.
This enraged Ikdros, who by now had cast his own daughter away for trying to stop him. During his fight with Uva something unexpected happened. An Angel defied him. One meant to watch the world and merely observe had finally snapped. His sorrow for the humans and even elves finally got to him and he could not forgive Ikdros.
In response Ikdros bound him in chains meant to sap his angelic powers and eventually lead to a slow and painful death. During this the Angel managed to draw on the chains and use them himself, using the surprise to help Uva defeat Ikdros.
The Angel used the chains to sap all divine power from Ikdros and unintentionally took it himself. This was Arakiel. The new God of Protection and Forgiveness. Uva and Arakiel worked together to do what they could to restore balance but by then the monsters had become part of the ecosystem so they left them be.
They did their best to monitor the three new lands which have become known as the island of Yuehai, a small mountainous island, the continent of Aurora as it has the strongest Aurora Borealis and has the most elves and humans, and Eden the safe haven of a new race called Nephilim. Nephilim came about from the war with Ikdros, Uva, and Arakiel. Demons and angels had gone to the continents and a few had children creating a new race that often showed their stark differences with random appearance like flaming wings or blue skin.
After the war and a thousand years to settle humans are doing better and slowly on the rise. Unfortunately some elves can be rather haughty and look down on them, causing quite a bit of friction. This usually stems from the fact elves can use magic as they were born with "Stars" which are like meridian points that can be filled with mana and moved for different spells.
Humans have learned to make do by crafting gear with monster parts and cores but a lot of elves still look down on them despite their coming back. Nephilim generally don't have this problem as they usually inherit something from their blood line.
In the most recent years there have also been rumors of a dragon race but this is unconfirmed, especially as a lot of the world is still undiscovered after the war of Gods.
There is now an adventurers guild that most people join and they even have a training academy. They can do anything from mundane chores for the elderly to exploring ancient ruins of the lost cities or hunt dangerous monsters.
Unfortunately demons still being a prevalent problem as well there is a hidden "guild" to hunt down adventurers when they are out. This has led to the use of old phones being repurposed and used to help send SOS signals in case of emergency and is a tool for connecting with friends or family.