The Awakened One Who Levels in Reverse

In a world where everyone receives a skill upon reaching level 50, Shun was given the "Level Down" skill. The more he fights, the more his level decreases, a worthless skill in the eyes of everyone. Having trained tirelessly up until that point, he finds himself getting weaker by the second. Eventually, he is almost killed by a low-level monster, but when he defeated it with all his strength, he finds his level has dropped into the negatives. Shun, confused, obtained the power of "the other side of the world." In this world, levels itself are a curse. Shun, freed from this curse, gains access to abilities that defy this world's rules!