Dungeons of the Crooked Mountains

Hard to get into first but becomes very good in the end chapters

This is unique in way, there are many books where hero has disadvantages but gains a unique ability after an accident and becomes super awesome. This follows the same concept but it is very much realistic. It follows the MC's struggles and how he overcomes his zero level. Hard to get into because in early chapters you feel the pity and helplessness of the MC but it gets better after chapter 15