I know this is super bad to start like this in the beginning but this is my first work and will have a lot of mistakes plz fill in the blanks as best you can that's all bye!
The people of this world's power structure are based on an innate talent or power that either can decide their position in society whether some mob to be killed so someone else can live or someone who has the power to protect themselves and live to the next day.
In this world there are 3 main races, elves, dwarves, and humans, of course, there are more but their overall importance is lower than the first 3, such as dark elves and dragons, dragons aren't too important due to their being a diluted bloodline their descendants are few and don't have more than a tenth of their ancestors powers, next dark elves are not oppressed as many other novels depict them as but instead are too few to be apart of the main three powers and instead are considered apart of the larger elves.
There are magical beasts ranked from F, E, D, C, B, and A rank respectively, similarly, adventurers are ranked the same, but 50 years ago the demon race emerged and began oppressing other races led by the intimidating demon king who possesses both master swordsmanship and the flames of hell his arrival changed the ranking system adding an S rank and SS rank, past that SSS rank but is said to be the realm of the god's.
The demon king as arrogant as he was granted a 10-year grace period before the war resumed destroyed everything beautiful and made rivers of blood using this time those in power focused on nurturing youths who may give them a higher chance of winning.