He and the Paranoid Non-Human Villain [Quick Transmigration]

There exists a type of antagonist who possesses both the fortune and strength to rival the protagonist, yet under the plot's heavy hand, they are reduced to mere stepping stones, inexplicably losing their intelligence and exiting the stage. To address this injustice, a righteous system has set its sights on the cannon fodder characters most likely to alter the course of events. System: "You only have a few days left to live. Help the antagonist survive key plot points, and you'll extend your life!" The mission proceeds smoothly, but... The host, tightly embraced and unwilling to be released by the antagonist, wonders: Is this life-extending deal even legitimate? 【World One: The Aloof an...