[Salamander8]

As far as R'Lyeh's void gate, any astral mage can use it, but the 150 gold starspawns have a lower chance of insanity than other astral mages. The named hero Cthugul has even less of a chance to go bonkers. I'm certain it works the same way in Dom3 as it did in Dom2 (I recall seeing a tip of the turn that mentions this as well).

As far as this site, it sounds like it's very much like the void gate. I've never seen it in any of my games though, so I can't tell you for sure.