In the surrounding forest, she charmed a dark fey with control over the Orb Weavers. She bore him a son, and then slew him and took his means of control: a magical harp. Her twisted, half-demon son was raised by the hermits until such time as he grew in power enough to slay them all with his mother's aid. They have been luring spiders into the caves and harvesting the Orbs as the evil son grows in arcane power. Recently, he has begun raising the dead spiders as zombies, and has summoned and enslaved a minor devil as a familiar.
For visualization purposes, the art to Ava Adore popped into my head, so here it is:
Lilin: A form of succubus.
Physically beautiful if somewhat unsettling, a lilin will always try to charm a subject, or flee if her attempt fails and she feels outnumbered.
3 HD; AC 4; 1 claw 1d6+1; move 30; charm person at will (but any target only 1/day); regenerates damage not done by magical or silver weapons: if reduced to 0 hp by other means will take gaseous form for 1d4 days to heal to full hp.
Right now she has a spider charming harp. (detailed tomorrow)
Abraxarius: Her wicked spawn.
2 HD; AC 9; dagger 1d4; move 30; controls zombie spiders; casts balefire 1/day. Carries one spider orb at all times, can be thrown as missile to cast web spell.
Smoking Devilkin: his enslaved minion.
A long, horse-like face on a twisted runty body. Can move faster than it would appear, but its gait is awkward and ambling.
2 HD; AC 6; 2 claws 1d4+1; move 20; can issue forth 20' radius bouts of smoke from its mouth every 1d3 rounds, conceals him (80% miss chance in melee, can't fire ranged).