Thanks Mocata, and also JadedSkywalker. The Charles Lippincott blog makes for a great a read through, some truly awesome stuff on there, and I’ve only just read a little of it so far.
Posts on TFN’s Jedi Council Forums tipped me off to Bataal Bandu, a Sith belonging to a faction in opposition to Vader. Luckily, the Internet Archive has a copy of the magazine he’s mentioned in:
https://archive.org/details/IQ.Gamer.Partial.Collection/inquest.043.(1998-11)/mode/2up?view=theater
Thanks Superweapon VII! Batall Bandu is interesting enough for his own comic after reading that article.
That Internet Archive has been superb for content in here, and for much older and no longer acknowledged content on the official sites in general.
I’ve added the article, links and a couple of screenshots to the Settings, Planets and Systems | Organisations and Governments section, in “The Sith” category #5.