Haleon is a world not unlike our own. Similar to much urban fantasy, magic was previously prevalent in the world, but it has since been largely forgotten. Modern society will look very similar to our own in terms of technological advancements. I am going to make use of modern similarities between this world and our own to focus on a different set of worldbuilding details. In particular, I really want to focus on the magic system, magical species and societies/cultures.
The World
Geography
Haleon is comprised of seven continents. There are no notable geographic features which would affect the world as a whole. The planet is constructed similarly to Earth.
Resources
The resources of Haleon are of a similar distribution to א-Earth.
Magic
Mechanics
Magic in this world plays on a dichotomy of stable vs. unstable magic. People often interpret this magic as good vs. evil, light vs. dark, whole vs. corrupt and many other labels which ascribe some sort of morality to the two sides, however in reality no such natural alignment exists.
Stable magics function consistently and predictably. Unstable magic, however, is much the opposite. While the general effect of the magics may be known, random side effects are extremely common. The tradeoff, however, is that unstable magic offers far greater potency. Unstable magics can pierce the veil between life and death, infect the mind and ultimately even alter reality itself.
Most magics are performed via one of three primary means. Incantation, ritual or communion with a deity, with incantation being by far the most common.
Additionally, objects can be imbued with magical properties.
Usage
Those who have an inherent magical ability have greatly reduced in number over the course of a couple of centuries due primarily to persecution by those without it.
Magic was originally granted to humans by the gods, and over generations of exposure they developed a natural affinity.
Those who are not descendants of those blessed by the magics of the gods cannot perform magic without either forming a communion with a god, or taking advantage of magical objects.
Gods
The gods which play a notable role in this world will be limited to the Old Gods and the Young Gods. However, the former are divided into two camps. There are the fundamentals, who embody the primordial forces of the universe, and the elder gods, who are the more participatory gods who spawned the younger generation and formed the world.
Impact
Magic played a large role in this world's history. The modern impact is more minimal, however, it is definitely still present.
Magic played a prominent role in setting up cultural and political divides which still last to this day. While often not leaders themselves, because leaders tend to change frequently, magical dynasties have influenced many empires, both old and modern, throughout history.
People
Species
The only natural sapient species in Haleon, excluding the Gods, are humans. While there will be a few others, they have all their been created by, or evolved through magical means. For example, the Fae were once human, however they have evolved into what they are now due to their prolonged and concentrated connection to magic.
Populations
The majority of the planet is widely populated by human civilizations, much akin to Earth. While some less hospitable environments will be more sparsely populated, most of the planet is fairly densely packed.
Politics & Government
Of the seven continents of Haleon: Astir, Kanapra, Handeheim and Koneg are far more prosperous than the other three. These four are also the most densely populated. Ursalva and Sigorrin fuel the global supply chain, acting as manufacturing centres. Vanemir however, is largely marsh and swamp land, making the construction of large facilities for manufacturing, processing or even just basic infrastructure difficult.
The Astir and Kandeheim are home to the two most prominent global superpowers.
Dominion States
A Dominion State is one which is ruled by a dominion. This is a fairly modern governmental system, first appearing less than two centuries ago.
Rika
A rika is a theocratic state run under the religion of Maruganna Semphis. In a rika, there are strict rules which enforce cultural norms. While there is significant cultural differences between different rika there a certain tenants core to Maruganna Semphis which are common among them.
History
This world was created by virtue of the of the Old Gods coming into being. In one faction, the Fundamentals formed the underlying structure to the universe, representing creation, destruction, death, formation, power, and more. In a second faction, the Elder Gods take advantage of the forces which the Fundamentals provide to build upon the blueprint laid out by the world's creation. They bring forth the mortals, granting powerful magics to those who earn their favour. They bring forth the fauna and flora of Haleon.
The Elder Gods rules over Haleon for millennia. Eventually, however, they grow bored with their creations and retreat to their own paradise, where they spawn a new generation of gods, the Young Gods. This younger generation wished to be free to explore the world. However, the Elder Gods forbid it, as they believe that their creation is perfection and that they could only taint it by venturing into it.
Eventually, the old gods are overthrown by a sect of their children. Their paradise is corrupted. The Young Gods descend upon the world and spread chaos. Eventually, the Young Gods also grow bored and many of them retreat other planes which they created. None, however, ever match the paradise which they destroyed.