Sorcerous Skull Swarm
CREATURE 14The act of creating a demilich sometimes goes horribly awry, leaving behind a shattered remnant of a once-mighty spellcaster constantly leaking eldritch energies. The ruined spirit animates a cloud of debased copies of itself, glittering with cracked crystals in crude imitation, and it hungers constantly for the magical energies denied it in its corrupted immortality.
Some of the spellcaster's personality remains in the swarm, albeit usually unnaturally split between the skulls. As a consequence, the skulls argue among themselves as warring parts of the personality clamor to be heard, resulting in the swarm's fractious, inconstant attitude.
A skull swarm is composed of reanimated masses of craniums and jawbones, forming a terrifying avalanche of undead fury. Most skull swarms are mindless, though some retain a vestige of wit, awareness, and even magical talents from life, culminating in a highly intelligent swarm mind.
A constant spell affects the monster without the monster needing to cast it, and its duration is unlimited. If a constant spell gets counteracted, the monster can reactivate it by spending the normal spellcasting actions the spell requires.
This monster doesn't have a single mind (typically because it's a swarm of smaller creatures), and is immune to mental effects that target only a specific number of creatures. It is still subject to mental effects that affect all creatures in an area.
When a sorcerous skull swarm is reduced to 0 Hit Points, it erupts in an explosion of foul energy and bone fragments in a 30-foot burst, dealing 3d12 piercing damage and 3d12 void damage (DC 34 basic Reflex save).
A creature with void healing draws health from void energy rather than vitality energy. It is damaged by vitality damage and is not healed by vitality healing effects. It does not take void damage, and it is healed by void effects that heal undead.
The sorcerous skull swarm saps magic from nearby creatures. Any creature with the ability to cast spells (including innate spells) in the swarm's space takes 15d6 mental damage (DC 34 basic Will save); on a failure, the creature is also Stupefied 2 (Stupefied 3 on a critical failure).
Each enemy in the swarm's space takes 5d8 piercing damage (DC 34 basic Reflex save).