This was the only way one could become a Martial Protector. For one to become the Martial Diety, he had to be a Martial Protector.
To become a Martial Protector, one needed to prove their loyalty to the sect and its ways.
There were a few ways to achieve this but many of them required luck. Kai Syaoran was not willing to leave his success in the hands of lady luck. He had to create his own luck.
After proving one's loyalty to the sect, the second step was for someone to nominate them to take part in the Mortal Combat.
Still, this was not enough for the sect. The person only other Martial Protector had the power to nominate people for this position. They had to be very careful since Martial Protectors were the cornerstones of the sect and if a spy wanted to become a Martial Protector, they could do some real damage.
After the nomination, the sect would carry out an in-depth investigation into the nominee's background.