The fat old man said this, and the Yin Celestial Son had no argument.
To integrate into the Returning Ruins and become the array spirit of the Returning Ruins.
Simply put, it's to control the Returning Ruins.
In fact, even the Returning Ruins Arena where the fat old man serves as the array spirit is under the control of the Returning Ruins array spirit.
This is akin to the fat old man being a retainer who needs to find a lord.
At the very least, this lord must be acknowledged by the fat old man.
Letting Lin Yuan enter the Returning Ruins on his own is, frankly, a kind of trial by the fat old man for Lin Yuan.
If Lin Yuan can't even manage to enter the Returning Ruins, then he doesn't deserve to become the array spirit of the Returning Ruins.
The fat old man spoke to this extent, and the Yin Celestial Son couldn't press further.
Continuing to press would just show he lacks tact.
"Since it's settled, let's stick to our agreement!"
