What do I need to get them?[DM assist]

[Lordnightshade]

Be really evil and hit the players with Dreammist from the BoVD (a drug that causes a euphoric sensation and incapacitates the victim making them easy to capture, it is also EXTREMELY addictive). Then have the crimelords thugs bring the drugged up PCs back to him. He will keep them with him for a few days giving them daily doses of Dreammist until he can be sure that they are complete addicts.

Then he will let them know what the deal is, since they killed his daughter, he wants them to exact revenge on themselves for him.

In exchange for more Dreammist, he will have them do things for him (these could include a PC killing his daughter/sister/other relation).

Of course he will always offer them death as an alternative, but they will have to beg him for it, or commit suicide.

If someone killed my daughter (I don’t have any kids but if I did) I would desire a revenge so evil and complete that those who killed my daughter would beg for the pleasantness of hell over what I would inflict upon them.

 

[Lordnightshade]

Ok, so you probably don’t want to completely destroy your game. So your PCs will need a way out of my afore mentioned predicament. The son (who has always felt that his father loved his sister more) helps the PCs with an antidote for the Dreammist (like Methadone for the heroin user).

Then the PCs will have to bluff their @$$e$ off to convince the crimelord that they are under the influence of the Dreammist and they will have to figure out how to give him the slip. Could be fun, and would set the crimelord up as a MAJOR reoccurring villain who the PCs will hate with an extreme passion.