Shank is known as a reliable source of information about the Commonwealth. In turn, his information comes from various caravans entering and leaving Nuka-World. He is integral to establishing raider outposts in the Commonwealth for the various gangs. When first encountered by the Sole Survivor, Shank can be seen talking with Katelyn about a settlement that was recently attacked by super mutants.
If creating settlements with the raiders from Nuka-World before starting When Freedom Calls, Shank will function as the raider version of Preston Garvey during Home Sweet Home, but with some advantages. Rather than assigning the Sole Survivor a settlement randomly from the total number of remaining unclaimed settlements, they will be able to choose the settlement of their preference from the entire list of available settlement options.
Capture will be the only available option for settlements that are linked to Taking Point. It will also be available as the violent option if the settlement is currently under control of the original owners, the Sole Survivor or the Minutemen. If chosen as the option for a settlement location currently held by settlers, all settlers will need to be killed (this includes settlers at settlements that are already allied with the Sole Survivor). This quest is unavailable as an option for settlements that have NPCs flagged as essential.
Clear Out will be available as the non-violent option for settlements controlled by the original owners, the Sole Survivor or the Minutemen. One Medium and one Hard speech check must be passed in order to run the current settlers off the land without bloodshed.
Subdue will be available as the violent option for converting a settlement into a vassal. This option will not become available until the Sole Survivor has already completed at least one of the two quests above. If the settlement is guarded, regardless of whether the defenses are simply turrets or also include patrolling settlers, the player character will need to eliminate any hostiles and severely injure the owner of the settlement. This might involve killing settlers that are already tasked with farming and cannot be replaced or reassigned while the quest is active. Vassal settlements are needed to supply other settlements that have been captured or cleared out, but do not count as raider outposts (with respect to the total outpost count for Home Sweet Home, Wasteland Warlord and Hostile Takeover.
Shake Down will be available as the non-violent option for converting a settlement into a vassal. The player character can choose to either bribe the owner into providing supplies for the raiders or pass a speech check if they have high enough Charisma. As with the quest above, vassal settlements created in this manner do not count towards the total count of raider outposts.
Shank provides the option to raid settlements even for settlements that the Sole Survivor already controls. If converting a settlement already controlled to a vassal, the player character will immediately lose all access to workshop mode once a gang is assigned to the settlement. Therefore, one will also lose the ability to assign settlers to specific tasks. Full control of the settlement can only be reclaimed by becoming hostile with any raider faction, which will allow the player character to reclaim the settlement once all the raiders that have been assigned to it have been killed.
Shank cannot be sent back to Nuka-World while the quest Power Play is active.
Shank will not be able to offer the Sole Survivor Cleaning House unless the gang that betrayed them during Power Play was given at least one raider outpost in the Commonwealth during Home Sweet Home.
The incompletable miscellaneous quest that tells the player character to talk to him about running jobs in the Commonwealth can be completed on PC via the console by typing the command: SetObjectiveCompleted DLC04ShankMiscObjective 10 1. Using this command will still let the player character do his quests without issue.
Shank will fight alongside the other raiders if the Sole Survivor decides to go through with Open Season.