Synopsis

Do you believe in hell?
Throughout my life, I always did, yet despite that, I've consistently acted as if I didn't. Going from one wrongdoing to another, I always believed that at some point in the future—maybe in my fifties or so—I would turn things around.
I aspired to become a good father, crafting enduring memories for my future offspring to cling to long after I was gone. A good husband for my blonde of a wife to mourn forever. A commendable individual who would be a source of inspiration—in other words, I wanted to become what would be considered by the world and perhaps even gods if they do exist—a good person. However, before I could reach that age, before I could become a good person, before I could earn myself a nice spot in heaven, I died, and the hell that I had long pretended to ignore came into existence, awaiting me.
The pain is excruciating, the burning is intense, yet I can't even let out a scream. I yearn for it to cease, but having been here long enough, boiling in this ocean of flame, I understand very well that it won't.
I know it's futile, yet if there is someone out there—anything, anyone—please save me. If you choose to do so, I will dedicate my existence to what truly matters.
Wanting to witness the release of the being he was intended to serve from her mortal seal, a strange entity from the astral seal tore through the very fabric of hell to reach Eldoria. In its descent, this entity inadvertently transported souls from the same infernal realm, souls that could only belong to one place—the very hell they had just escaped. Taking on new forms, bestowed with a system, and entrusted with the mission to sow chaos, these souls were set loose upon Eldoria.
In the world of Eldoria, a realm brimming with swords, magic, roaming monsters, and various sentient humanoid species, numerous dungeons are scattered around.
With treacherous passages, concealed chambers, randomly appearing monsters, unfathomable secrets, and illogical biomes, each dungeon distinguishes itself from the others, while also sharing traits with all the rest. However, there is one dungeon that stands apart.
Follow the story of not of a man (no longer defined as such), not of a mere beast (though it could resemble one), but instead, of the sentient being behind Eldoria's first and oldest SSS-ranked dungeon.