Planet name is Aurelia, its very similar to Earth yet distinct, it's around 1.5x earth radius, with seven major continents:
1. The human continent(with the human empire and Holy Church where they worship Eos(empire is divided into the state(imperial family and nobility) and the holy church of Eos).
2. Vampire continent(Ruled by the Royal Vampire Family)
3. Elven continent(Ruled by Elven royal family and the elf Queen and King)
4. Beast-kin continent(with various beast clans, the leaders though are the Kitsune clan, Wolf clan, and Serpent clan)
Then the other 3 continents are already conquered by the demons and are demon strongholds, full of demonic energy and hostile towards all non-demonic life.
Geopolitics are simple, everyone hates demons, common enemy means working together to fight said enemy, even if all the races have prejudice toward each other. Also demons are not native. Demon lords are as follows:
1. Lucifer the Demon Lord of Pride(de facto leader and wants to get rid of the mortal races to spite the gods)
2. Asmodeus the Demon Lord of Lust
3. Belphegor the Demon Lord of Sloth
4. Satan the Demon Lord of Wrath
5. Beelzebub the Demon Lord of Gluttony
6. Leviathan the Demon Lord of Envy
7. Mammon the Demon Lord of Greed
So common enemy is biblical hell, demon lords and 72 keys of Solomon. the more powerful the demon, the harder it is to leave hell, you need souls to do so, this is why demons aim to make contracts with mortals to gain soul ownership and why Lucifer doesn't just dues ex machina.
Also important to note, there is one sun and moon and the vampire queen(the ruler of the vampire race) cast a spell that keeps the entire Vampire continent shrouded in endless night, vampires don't turn to ash in the sun, thats only peasant vampires, noble ones have much higher sun resistance and it scales relative to noble house rank, with the royal family having perfect sun immunity. Also because the vampire queen has a special tier-10 innate ability tied to the moon, her continent wide spell is sustained by lunar mana.
Also mana is due to mana veins inside the planet, mana saturates the entire world, with the elven continent having particularly high mana saturation and density. And for the holy church of Eos, a Saintess candidate is always chosen per generation.
Antagonists are demons, specifically the ones from the abrahamic pantheon, with it following the 72 keys of Solomon and Lucifer being the ruler of biblical hell(though of course, there are other Underworlds for different pantheons, but the biblical hell is the enemy), and all gods(including angels), regardless of pantheon, hate the demons, they just feel 'wrong' to divine beings, like corruption made manifest, but because divine beings aren't allowed to directly interfere in mortal affairs means that they cant directly eradicate the demons, and Lucifer's goal is to wipe out humanity to spite the gods, particularly yahweh since he knows how much yahweh likes humans. Also for biblical hell, lucifer is of course, the demon lord of pride. Asmodeus is the demon lord of lust, Beelzebub is the demon lord of gluttony, belphegor is the demon lord of sloth, demon lord of wrath is satan, demon lord of envy leviathan, and demon lord of greed Mammon. With lucifer being de facto leader essentially. Also
but because they are also bound by the same rules as the gods, they cant directly interfere with humans because they're too strong, they can however, have the 72 keys of solomon and demons under their banners fight the humans and have them try to tempt humans to give up their souls, because to break the rules, lucifer needs enough human souls as the price to descend on earth(higher soul rank potential souls are worth more than lower ranked ones as well).
Important to note that mana is everywhere on the planet, and demonic energy is everywhere in biblical hell. And to rank up(say from G- to G and so on) you need to absorb mana and refine it through your mana core, soul rank potential combined with natural talent dictate how easy and fast this process is.
Also it isn't a coincidence that all the main players arrive at the academy, the academy is designed to attract the most talented to mold them into future pillars to fight the demons, all of the races came together to help build a 'global academy' in a neutral continent and agreed to send their most talented there, plus there is racism and xenophobia present, humans typically view beast-kin as 'savages', elves view humans as 'annoying, egotistical and use mana crudely', vampires don't really care, they view most other races with indifference, humans view vampires as 'leeches', and elves view all the other races as inferior to them because of their natural mana affinity and longer lives. So at the academy, tensions are naturally high, even if the academy has strict rules around no discrimination allowed. Academy arc will likely be around 500-600 chapters based on current outline, but the entire novel is predicted to have around 2500 chapters total by the end, so don't worry, the Academy will not last forever.