Would you be interested in either investigation or dreamscape? Investigation would be a nice and natural follow-up to the conversation they've already had at the party, as Venera opens a new location entirely. And... While they don't call it "Inquisition" where she's from, dreamscapes would be a convenient way to trip on the ??? of "so we both have church ties of the strong-arming variety ft. an actual vampire and a certified vampire hunter"? Taking care of/keeping an eye out for could work too, Ciel is very much on her way to nosy into every Kenoma's business so if you'd like to be saddled with a long-term meddler, this could be the starting point (I realize this is a terrible sell, but,)?