Toxic Tank

Kai is the Janitor of the Abyss—the lowest-ranked sanitation worker in a kingdom that pretends rot doesn't exist. He scrubs sewers, hauls toxic sludge, and survives on stew that may or may not contain rats. He is not the protagonist of this world. Then the Oracle's voice descends from the Royal Dragon Bureau and assigns him a single, impossible task: clean the East Rot Pit. Inside it, he finds a Disaster-Class Rot Dragon the size of a plushie. The dragon offers him a contract. What Kai gets in return is the ability to digest filth—any filth. Toxic mana. Mutated bile. The decay nobles spend fortunes pretending isn't happening beneath their polished marble floors. What he doesn't get is permission to live quietly. Caius von Argent, the strongest knight in the Kingdom and its most terminal clean-freak, takes one look at Kai and decides he is a stain that must be removed. By the law. With paperwork. Slowly. Marie, an immaculate maid who died three hundred years ago, decides Kai's shack needs renovating. A slime named Viscous decides Kai is a toy. A noble girl named Elise gets parasitic mushrooms and a new career in sanitation. The Kingdom's pristine surface is starting to crack, and something underneath is breathing. Status: Completed (90 Chapters)