I was going to amend the saved post story on Krakii, but I think we should discuss it here first. Here is the topic: http://www.krakiipedia.org/wiki/Darkstone_Castle_(saved_post)

It's from Banthis and he essentially says he has no idea where Darkstone comes from. It was initially named Claedesbrim of course like the Bay and adapted to be run by Estrion. The original Quellbourne module is probably the genesis of the area, as mentioned by Banthis. This most likely was Quellburn, the capital city of the area/realm known as Quellbourne and where Kelfour's/Wehnimers was located, and a reference to it's crazed Sorcerer Zenon is made in one of the original Kelfour Editions. (They had a habit of reviewing ICE modules occasionally)

Similarities between Zenon and Estrion are a stretch, but only a blurry one. Strikingly though they are of similar level design and included Tergon's, which would become Roa'ters in todays vernacular. After that I think it's a hodgepodge of ideas, but it seems to fit.