Transmigrated into the Protagonist's Cannon Fodder Ex [Quick Transmigration]

'''"Don't overthink it—I'm still that ex-boyfriend of yours with the most difficult personality, the worst temper, the sharpest tongue, and the hardest hits." Shen Zhi is bound to a system that tasks him with playing the role of the toxic ex-boyfriend of the protagonist gong in various small worlds, carrying out missions to persecute the protagonist gong and highlight the "true kindness and beauty" of the protagonist shou. As a newcomer to the Time-Space Administration Bureau, Shen Zhi doesn’t dare slack off in these small worlds. He strictly adheres to his cannon fodder persona and diligently follows the plot points. But who could explain to him why, in the end, the protagonist gong acts...