Sudden Death and Rebirth: I Went into the Ring with the Black-Hearted Boss

"At the end of your life, what do you most want to achieve?" "I want to... Get in the ring with my boss!" "I will fulfill your wish..." I died suddenly after working overtime and was reborn. In this life, I will make the black-hearted boss pay the price! I've finished shouting slogans, and you're going to give me an auxiliary golden finger? Okay, okay, let's play like this... Look at me still growing up, climbing all the way to the top! The mastermind behind the scenes was also found out, no one can control my life! In this life, I will never be inferior to others!