The dynamics of the conversation shifted the moment Rui revealed the Silas Clan and the Elder Tree as bargaining chips. Now, it was almost as if the Divine Doctor was more eager to negotiate with Rui than the other way around.
Both of them knew the Divine Doctor would be lying if he said he was an asset that was equal in value to the Silas Clan and the Elder Tree. In fact, Rui knew that he would probably struggle to compete in value against even one of them, but he didn't mention that at the moment.
"Access to prophecy and the Elder Tree is a continuous service," Rui informed him. "If you want continuous access to prophecy, you need to provide continuous services to the Kandrian Empire."
A continuous service was generally more valuable than a one-time service, assuming all other variables were equal.
"…Be that as it may, I cannot search for Gaia's illness if I practice medicine in Kandria," he retorted clinically. "I cannot forsake my mission."