Naruto: The Outsider's Resolve - Chapter 9.2 (317)

The Northern Ice Fields had no boundaries.

The Winter Wolves hid within the snow, the Frost Tigers growled incessantly, and the roars of Giants echoed throughout the land. Many species struggled to survive in the icefield. At the same time, a baby White Dragon possessing the power of time broke out of its egg and opened its platinum-colored eyes.

Years later, the legendary Time Dragon appeared, moving freely between the endless past, present, and future.

Noboru Chikara is a forsaken prince burdened by neglect and betrayal. Blamed for a devastating attack by his family to protect his siblings, he endures abuse and prejudice from his family and people of his kingdom alike as his family accuses him of being possessed by the very beast that attacked the kingdom. Driven by an unwavering spirit, Noboru sets out to reclaim his birthright and forge a new, uncorrupted kingdom. But when his father commits a heinous act, Noboru's quest takes an unexpected turn, propelling him into a realm beyond imagination. Follow Noboru's journey as he transcends dimensions and becomes the one who bring peace to all dimensions higher or lower and become The God Of Fiction.

A normal guy gets hit by a truck and isekai'd. Why? Because trucks are apparently some cosmic loophole. He decides to be a dungeon, because it sounds weird and interesting to be one. Is it? Let's find out.