Boxing Porter

Modern-day dungeon society is in its first week of awakenings. Jack Cash works as a porter for an adventuring group until he is separated from them inside a dungeon and bitten by a strange dog. The bite awakens Limit Break: whenever Jack nears death, his strength, speed, and agility rise, while some damage converts into more power. Each surge leaves him desperately exhausted, and that weakness may become the cost that breaks the world.