The worst atrocity possible?
I have an inspiration:The dwarfs must be given access to the single gratest human atrocity of the late 20th century: reality TV
I propose that one prepares an embark on a site with at least one savage and one evil biome square (they needn't be the same square)
Your starting 7 are the production crew, your expedition leader is the host. you have roughly one year to set up a compound to house the production crew and keep the contestants separate from them. The compound should include various fenced off areas that will act as challenge rooms and the council chamber.
Once your migrants arrive, they are the contestants. They will need to survive as best they can. Every so often, you will cold challenges in the various challenge chambers. The challenges can be anything from crafting to combat. successfully completed challenges can include rewards for the outcasts, and other challenges can be for elimination. in the later case, the dorfs will gather in the council chamber, and the loser(s) will be made to pull the lever of failure.
each migrant wave is a season (or multiple waves if you get small ones), the winner of a season (and maybe the runner up) may join the production staff, or enter retirement in the compound (the runner up would act as servant for the winner)
if you get a sufficient number of nobles, you can have a celebrity edition of Survivor:DF, the winner, in this case, get's an all expense paid trip to the bottom of the lava tube.
if your fort lasts for enough 'seasons' you can bring your retired dorfs back for an all stars season