I was moving some old gaming books this week when I came across my Eberron hardcover. Back in my 3e days I played in a short Eberron campaign and liked some of the ideas (particularly changelings, shifters, and the artificer class).
I stumbled on this description for the Gatekeeper druidic sect:
The Gatekeepers are a druidic sect dedicated to keeping Eberron free of “unnatural” external influences, and this order has battled extraplanar invasions and aberrations for centuries.
These druids maintain old wards cattered around the region, seals that hold the daelkyr and other ancient powers in check. They also watch the skies for deadly planar convergences.
Okay; so that’s pretty cool – a druidic sect devoted to fighting otherworldy horrors. I’d like to swipe this for Hyperborea.
In Astonishing ACKS, the Gatekeeper sect works much the same way as described for Eberron, but against much longer odds. I already wrote up a version of the Ranger class with an appropriate special ability; here it is statted up as an ACKS proficiency:
Otherworldly Enemies: Trained by the druidic Gatekeepers, the character is furnished with the terrible knowledge of alien species and the nameless horrors they represent. Through the instruction he is provided the most effective means of harming them.
The character receives +1 on attack throws against aboleths, crab-men, elder things, fish-men, the Great Race, mi-go, night-gaunts, spore-men, and tentacular horrors. At level 7, this bonus increases to +2, and at level 13 it increases to +3.
Gatekeepers would make a good “heroic” affiliation for PCs in Hyperborea. I might do a new class writeup for Druids, and will add Otherworldy Enemies to the Bard proficiency list. (Rangers are trained by the Gatekeepers, and some Bards are also affiliated.)