I'm the Only One Who Knows That Jobless Is the Strongest

Story:

Dungeons have been appearing in the world for the past few years. Hunters, the cornerstone of dungeon clearing, have jobs with their own characteristics and abilities. The one who is said to be the weakest of them all is the Unemployed. He has no character traits or abilities. That is why it is not even thought of as a real job. However, Meguru rises to S-rank hunter with this very job and challenges the Celestial Dungeon, which is known as the greatest obstacle. He was working with other S-rang hunters, and just when he thought he had defeated the last boss… He was stabbed from behind. The other S-rangs betrayed him. As he let out his last breath, his sister Kanna was also killed. "I will never forgive you. I will kill every one of you…!" Meguru was reborn with this obsession. He reincarnated into a girl who looks exactly like Kanna. And just like the last time, his job was "Unemployed" … With the knowledge of his past life and the future power of the unemployed, Meguru will dominate everyone and everything. He begins to conquer the dungeons once more. This time with the ultimate goal of revenge.