The demilich is so named because, depending on the GM, it is either half a lich or half a demigod. At least that was the case with the world’s (oldest role-playing game’s) most famous demilich, Acererak from Tomb of Horrors. No wonder, then, that in 3.0 it appeared in the Epic Level Handbook.
Pathfinder’s version is a more reasonable CR 14. This makes sense, as it’s only a vestige of the original lich formed when the lich’s mind wandered too far or succumbed to ages of inactivity. As such, it’s mostly a guardian doomed to stand watch over its own silent tomb. But it’s still packed with nasty special abilities (Devour Soul (Su), especially) and hefty resistances, so PCs will be glad that its default setting is torpor, not dogged pursuit.
Plus there’s always the chance the lost spirit will come back. In that case, the awakened demilich is the monster for you…and if you want a truly character-crushing, Acererak-style bad guy, you can always use a mythic lich as the base creature…
Speaking of which, Acererak’s shadow does loom large, even in Pathfinder. Even players truly committed to staying in character are going to have a hard time reacting honestly to a gemstone-studded skull—they know it’s a demilich. To avoid this, it’s totally fair to present demiliches in some other fashion. Perhaps the soul gems could be gleaming ivory teeth, intricately carved chess pieces swirling around the undead like ioun stones, candles lit with black fire that never go out, etc. Just a thought…
The archdevil Mammon offered the lich Xeniabus access to one of the greatest libraries in the world—his own, naturally, stuffed with tomes carefully hoarded over the centuries. The lich accepted and became so lost in his studies that his body crumbled away. This, of course, was Mammon’s intent, and now the pathetic demilich guards a largely deserted satellite branch of the library, animating the dust, old quills, and scattered paperweights into a vengeful telekinetic storm.
Not all demiliches form from skulls. Korbus, a specialist in sonic spells and words of power (see Ultimate Magic), claimed a holy cantor’s mausoleum for his lair while he pursued his studies. While his mind was adrift, relic hunters mistook his corpse for the saint’s and confiscated his well-preserved vocal cords. Enough of Korbus’s essence clung to the organs to animate them as the core of a demilich. Now installed in a shrine, the demilich uses its jewel-encrusted case to house devoured souls, and if forced into a confrontation, it uses a telekinesis-animated skull to distract from its true location. Canny adventurers might realize the demilich’s wail of the banshee comes from the preserved organs, not the leering skull.
Son of the demigod of generals, a nephilim met the lich Tai Shan on the field of battle. He cleaved Tai Shan’s head from his body with a divine blade, then smashed the ark that served as the lich’s phylactery. Enough of Tai Shan’s spirit remained that the skull endured as an awakened demilich, even as the nephilim carried it halfway across the world as a trophy. Meanwhile, the body was food for worms...until it rose as a worm that walks. Now, two centuries later, the two halves of Tai Shan seek to reunite, and their plotting will eventually ensnare two nations, the demigod’s son, and some unlucky adventurers.
—Pathfinder Bestiary 3 66–67
I saw the vocal cords of Saint Anthony in Padua. They were…something.
I actually don’t know that much about Acererak and the Tomb of Horrors aside from various Dragon/Dungeon retrospectives and the Nodwick and Jason Thompson comics about them. Even the publication dates seem to conspire against me: I’m too young for the 1e versions, the 2e reboot came out when I was in college, far from any game shops, and the 3.5 free Halloween download came out three weeks into my scary/overwhelming pro DJ gig. (4e’s version was simply 4e.) …And, having typed all that, I realize that none of the is the slightest bit interesting to you, the reader, but it was helpful for me in figuring out why I have almost zero reference points for this Important Gaming Touchstone™. (Biography can be like that. I’m like the only person in my generation not scarred by the Challenger explosion because I was home sick that day and my mother wouldn’t let me near the TV.)
I’ll post my radio show tomorrow—I am beat and need sleep.