The Ruthless Dead, irredeemable Oathbreakers who did not follow Aragorn, are still within the Paths of the Dead.
'Many of the Oathbreakers appear to have marched with Aragorn. A group of them however, the Ruthless Dead, refused to accept his offer and now stew within the tunnels and caves of the Paths of the Dead. They are beyond redemption. Though they cannot be killed, they can be quieted for a period.
'Kêr Izel is within the Paths of the Dead, far north of here. Venture within and quiet any Ruthless Dead you encounter within.'
Ruthless Dead can be found within Kêr Izel, in the Paths of the Dead, far to the north of Dol Amroth.
Golusel asked you to quiet the Ruthless Dead within the lower city of the Paths of the Dead.
Golusel is in Dol Amroth.
Golusel will be pleased to hear many Ruthless Dead have been quieted.