I really want my Big Bad to have a big emotional impact on my characters. Since he's going to be amassing a lot of personal power and since the players disrupted a big part of his operation, he wants revenge on them.
The problem is that there's little he has he can threaten them with. The four of them have few ties outside their own interests, and each other.
I've thought about having him murder a group of children and transmit the gruesome images to the PCs, since they have actually gone out of their way to save children in the past. Sort of a, "Look at the consequences of your actions, you pitiful do-gooders." Anyone have any ideas that might work along these lines?