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

Dungeons have been appearing in the world for the past few years. Hunters, the cornerstone of clearing dungeons, each have a job with its own traits and abilities.
The one said to be the weakest among all of them is “Jobless”. It has neither traits nor abilities. That’s why it’s not even thought of as a proper job.
However, Meguru rises to an S-rank hunter with that very job and challenges the Sky Dungeon, which is known as the greatest obstacle.
He worked with other S-rank hunters and, the moment he thought he’d defeated the final boss… He was stabbed from behind.
The other S-ranks had betrayed him. As he took his final breaths, his sister Kanna was also killed.

“I’ll never forgive you. I’ll kill each and every one of you…!”
Meguru was reborn with that obsession.
In his new life, he finds a girl who is the spitting image of Kanna.
And like last time, his job was Jobless…
With the knowledge of his past life and the future power of Jobless, Meguru will dominate everyone and everything.
He starts conquering dungeons once again. This time with the ultimate goal of revenge.