Was doing a search on Vorakesh and found this nugget-rich mine of data from the older Runebound games, might give creatives some more ideas for stories, enemies and even heroes as it mentions a few I'd not known of until today:
Sir Gareth the Black (some people may prefer to rename him- many see the association of black with evil as somewhat implicitly racist, can see their point, I often substitute things like shadow/darkness etc)
Cardinal Koth (which for some reason sounds a bit Star Trek )
Jirta the Fierce
Runemaster Baras
and @rugal - wonder if the earlier versions of the Margath story differ to the current edition- I like the idea of a Vorakesh link- I've decided my 'Wandering orbits.....' campaign will be set in the fifth darkness so may work the Margath's return story into a campaign preceding it set around the fourth darkness
https://boardgamegeek.com/geeklist/62445/collected-histories-terrinoth