The Bottom Adventurers Start by Catching the Full-Level Succubus.

After traveling through time, Ragnar was unable to find his golden finger, so he could only make a living as a low-level adventurer, fighting monsters like slimes and goblins. He originally thought that this would be the end of his life, but unexpectedly, he encountered a full-level Great Succubus. The other party took pleasure in ravaging human beings, and the magic in his hand could break mountains and seas. The most important thing was that he was only eight meters away from her at the time. ... Then he won the battle and signed a master-servant contract with the succubus. But he won the battle, but he was also cursed, and he fell into the curse. In order to survive, he had to take this dangerous succubus on a journey to lift the curse. What bad luck. [Contract with the succubus: Devouring souls can upgrade abilities. It's not particularly unlucky.