Surviving in Hanna: My System 100x

Trapped in a secret CIA facility under the relentless gaze of Marissa Wiegler, Arthur was just another disposable employee. Until the day the VIP Target was captured: a wild, lethal blonde girl named Hanna. The moment her eyes met his, Arthur's world changed. A warning echoed in his mind. The [100x Multiplication System] had awakened. With attributes ranging from a pathetic [E-] to a legendary [EX], Arthur will need to use his newfound power to survive the chaos Hanna is about to unleash. Every gain, every workout, every reward is multiplied by one hundred. And to escape this hell, he'll need to make a deal with the facility's most dangerous weapon. — Description from novelcodex.org