[The qualification was hidden. A convergence of extreme emotional pressure, a will pushed to its breaking point, and the potential for significant metaphysical change. You met that threshold. And thus, you won the System.]
'Won the System,' he thought. So it wasn't just a random assignment. He had, in some way, earned this, even if the earning had come from the worst moments of his life.
"Are there others?" He asked, a new thought striking him. "Other 'players,' like me? Did they meet different qualifications? Get different rewards?"
[Yes. Other individuals have been chosen. They met varied qualifications and received rewards commensurate with those catalysts. Some received innate abilities, others specialized artifacts, or unique knowledge.]
He considered that. Other people out there, with their own systems or powers, chosen for their own reasons. The world was a lot bigger and weirder than he'd initially thought, even after the dungeons and monsters.