Strongest Tone-up System

Yang Rui, an ordinary man with no extraordinary talents, plans to propose to his girlfriend, Li Li, with a ring he has saved for months.     
Just as he is about to surprise her, a call from his friend Zhang Peng turns his life upside down.
With his engagement shattered and betrayal revealed, Yang Rui finds himself in despair until a mysterious orb interrupts him: "Do you wish to bind yourself to the Strongest Strengthening System? Yes or no?"
What is this sudden intervention, and what fate awaits Yang Rui now?