C1207 A Quasi-saint Card in the Auction System
According to the introduction, it was actually very simple. It was to put a card that he didn't need into it and then send it to the auction, setting a base price. If the final bid was higher than the base price, then it would be sold. If it was lower than the base price, then it would naturally be ruined.
There would be some other types of cards appearing in the auction system at random times