Strongest Level 1

The raid failed.
In a desperate situation due to the impending suicide bombing of the dungeon boss, Lee Gon-woo was betrayed by his teammates, and abandoned in the boss’s room. Just when he thought it was all over, a dagger suddenly fell into his hands. And from that moment his life changed dramatically.
His life was saved, but all the levels he gained with such difficulty have reset, making him level 1.
[You have caught a “mosquito”. Your level has increased.]
“My level should have gone up, but why is nothing happening?!”