I Became a Prisoner Trainer in the Dungeon

In the web novel 'I Became a Prisoner Trainer in the Dungeon,' a reincarnated protagonist navigates a fantasy world devoid of special powers. Captured by a commander from the Demon Lord's army, the protagonist is coerced into becoming a s*ave trainer for human captives in order to survive. The high-stakes nature of the training, where failure equals death and a unique time-travel mechanism tied to a specific event, adds depth to this adult fantasy novel that delves into psychological themes amidst a backdrop of tragedy.