The last item on the auction block is the mysterious yin-yang-dragon pill. It's so rare that only two people have succeeded in making it. The pill was created by Gu Ling when he was just a lowly 5 star ancestor. Gu Ling was seriously wounded and pitied by his enemy, but he came back to the world and became a "dou venerate" . This is why Gu Ling wants you to not use the pill or afford it. But even Gu Ling, great as he is, has barely survived the pain of the battle. He's leaving because he doesn't have enough money to pay for the last item. The big sister shows him where to get the money to buy the pills. He also shows them a warehouse where they can buy the ingredients for the pills and the essence flame. The warehouse is also where they'll find the key to Elder Qing's house. He can still remember the aura of the elder, but it's gone. There's no way to cure the sect's "blood poison" , he says.