Once you open the Isle of Khaylmer as a Rite location, the small drive-imps will request during a Rite a feat you can complete with your given characters in the active party. It might ask something like simply dousing the pyre without passing, Banish and then douse, or Banish a large amount of exiles. If you want to, you can focus your effort on that instead, as it does give a small amount of gold you can use later.