To be safe, it has to be a marketable divine figure.
As for the form of the divine responsibilities, Sun Yan chose the transaction.
The reason is that judgment is too extreme, prone to unforeseen issues, and it's very likely Sun Yan himself couldn't control it.
Protection cannot solve the believer's problems, and the same goes for teaching, since believers come to pray to the divine, meaning they can't solve it on their own.
So, teaching them to rely on their own abilities to solve it is like taking off your pants to fart.
Only transaction won Sun Yan's favor the most; when believers have needs and want something, they must first give something.
In this way, the divine doesn't act for free, maintaining dignity, and believers won't feel their prayers are unanswered or that worshiping the divine is useless.
In this way, a fairly reliable faith cycle between the divine and believers can be established.
Compassion, divine being, transaction!
