Sinner is a raider leader in the Commonwealth, being rather possessive of his territory. He leads his men against any he considers a rival on his turf.
Depending on choices, Sinner and his crew may try to start a fight with any of the Nuka-World raiders under the Sole Survivor's leadership. He can either be talked down or be killed in an all-out gang war.
Home Sweet Home: Sinner and his crew must be dealt with at the gang's new location. Sinner can be intimidated with a Hard Speech check, otherwise, he has to be killed. If one chooses the "work together" option when talking with him, he will instantly turn hostile and attack the Sole Survivor and their gang.