Let's start a story with a simple premise about a modern world with superpower. Humans live in harmony (kind of) with other species of sub-human. There are 5 main races:
Human: The majority but usually regarded as the weakest individually but is the most dominant due to technological advance.
Werebeast: Can transform to other animal races, some have animal features. The strongest physical strength species.
Vampire: immortal but allergy to sunlight. They can use blood magic and have high physical strength. They reproduce by turning others into a vampire. But since normal vampires don't have this ability, only nobles do, vampires have the least number. In vampire society, the longest living vampires are the strongest since their strength increases through age. Lesser vampires cannot reproduce because those whom they tried to turn will become mindless monsters called ghouls.
Elf: Long lived and tall human who can control nature. Their number is reduced due to human's deforestation attempts.
Dwarves: Short, hairy, lives underground. They are said to master crafting and mining due to their power to control metal and earth.
Some time ago, gates opened throughout the world and monsters came out. Only those with superpower can protect the Earth. Other species of sub-human suddenly become popular to human society due to their special power to fight monsters after a long history of being hunted and prosecuted by the most technologically advanced human.
Those who travel through those gates will meet the dungeon. One can only close those gates of dungeons through destroying the heart of the dungeon, a dark stone in the deepest part of the dungeon. Those who try to close dungeons and fight monsters are called hunters.
The story begin with our protagonist, Hugo Gentoshi accidentally killed his own family in an accident upon awakening his power of dark flame.