[X] Plan Hail to the Queen
-[X] Use Intimidation Excellency
-[X] Question the vampire
—[X] The nature of the mission his group is on
—[X] What Lady Eiko is like
—[X] what forces he's aware of in the area
-[X] Use the Crown
—[X] On the vampire: "What does the ultimate faction behind this messenger know of what they call the dark seed?"
-[X] Stunt: "
Akuma " Molly begins, in a soft voice that doesn't so much carry over other sounds as deaden it with its passing, "I have need of your services still".
-[X] As her countless eyes open to seek answers, she pins her unnamed companion beneath the weight of her regard. "Answer me truly, promptly, and with all possible diligence and it will be as a messenger"
or lie and serve as a message promised the venomous courtesy threaded through her words.
-[X] Send the vampire back carrying a message changing the location to Mac's pub at noon on the same day, and carrying an email to negotiate further details through.
Not sure about the last bit, it's mostly just to poke them back for poking us.
It doesn't actually, one of the hooks of Iris Bulb Commerce is that it doesn't give the Yama King any control or influence until the bargainer loses the last bit of their soul - but you never know how much of your soul you have left…
Even if they don't have a way to mind control him they still have a good supernatural link and the possibility of good old fashion pressure games. The possibility of owning his own soul again could lead a person into all kinds of unfortunate decisions.
Edit: fixed some errors