The Deal
"I can't refuse your offer, but I need to know how you are going to give me your body in a month? That's fair, right? I want an assurance that you are not tricking me. In exchange, we can put your second clause in the contract that I will lose the right to your body and also will lose my memory of my research of your body if I ever betray or go back on my words in serving the Tang Empire. The Spiritual Contract overseen by the System is more reliable than a mere oath."
The atmosphere calmed down as the black smoke dispersed and Vandir became calmer. He was willing to listen first instead of jumping to conclusions. There was nothing to lose from listening to what Tang Shaoyang had to say.