An adventurer with the lowest rank, raising a brave girl~ Wasn't I just a middle-aged man? (Associated Names)

In an experiment to create artificial black holes or white holes for energy generation, things went awry. Instead, it opened a portal to another world, but not a friendly one. It connected to the dwelling places of creatures known as monsters. Amidst this chaos, individuals with supernatural abilities, similar to the monsters, emerged. They were…