If you're talking about Grey fold, then you have to become friend both of Debris Walkers and Rusty gang. After they both give you the keys to destroy the respective clans, you have to talk to Rusty's daughter. You need to increase your charisma to convince her to stop the war. I suggest you to wear the necklace that lady unicorn gave you (I don't remember her name, maybe Susan?), the red light club dress, the chains at your feet or the high heels, and if it's not enough, buy a beer and drink it before talking to Rusty daughter.