Danmachi: The Focalors Familia Starting from the Dungeon

The transmigrator Aiden possessed a cheat known as the [Intertwined Fate]. For sixteen years, it remained dormant, barring him from receiving a Falna. That changed when the God of Justice and Water, Focalors—who had been accidentally stranded in Heaven—finally descended to the lower world. As the Goddess descended, the Falna was inscribed. Soon, Robin’s singing voice echoed through the city, and Tifa’s fists shook the Labyrinth. However, Aiden's passive skill, [Abyss Gazed Back], spiraled out of control. The Dungeon began to birth monsters that should not exist. Abyss Mages chanted forbidden incantations, Cryo Whopperflowers bloomed in silence, and Pyro Regisvines took root in the deep layers... until the phantom of the Judgment-Class Honkai Beast, Benares, unleashed a thunderous dragon roar. Orario's common sense crumbled. The Guild descended into chaos, while the gods trembled in a mixture of euphoria and terror. "Behold, Aiden. This is the 'possibility' you have brought." ————— — Description from novelcodex.org