MTL - Super Dragon Cultivation System - Chapter 53 Breakthrough begins

The low-ranking behemoth, the iron mountain is invincible in the horizontal push, and it is called the king of the backing.

- Description from novelbuddy

After accidentally falling, she actually finds herself bound to a Second Female Lead Counter Attacking System!

Every little girl's fantasy is to live a wonderful life full of riches and luxuries. This was the future she imagined, and she was willing to go to any length to obtain it.She was spoiled, pampered, and doted on by her family, and she was proud of herself. She knew she deserved the best, and she went for it. This, however, is where the nightmare began.Wanting to leave the clutches of poverty wasn't as simple as she believed, given the things she had to give up, the humiliation she had to endure, and the numerous things she had to lose. It was not worthwhile.When she thought she had it all, she was slapped in the face with the cold, hard truth: she was only a SUBSTITUTE.And when two of her closest companions turned on her and betrayed her, she was shoved aside and got humiliated by people she used to know.With nothing and no one to lean on, she was forced to make decisions. Decisions that gradually resulted in something breathtakingly amazing.[DING! SIGN IN! THE HOST HAS BEEN REWARDED WITH ******]

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.