Many atrocities were committed by the people of The Vale during their Purge of the Orcs a century ago. Some of those horrors are celebrated in festivals dedicated to heroes of slaughter. There are also more secretive atrocities. Things the Common Folk never tell visitors.
One such unspeakable act created the abomination of the Tortured Wood. Terrible magics, unremitting butchery, and pure hated thinned the barrier between the physical world and a place of cold despair. Shadowy monsters roam the woods, the trees grow with unnatural aspects, and those who stay too long under those dark boughs are twisted into something else. It is rumored, though unconfirmed, that this is where the Vale’s small population of Shadow Children come from.
The magics used to obliterate the orc stronghold that once stood at the center of the wood had many unforeseen consequences but some of the more bizarre things birthed from the conflagration are Living Spells.
A Living Spell is a barely sentient a swarm of magic that constantly recreates whatever spell birthed it. Some are benign on their own, like Slumber Fog, but others are intensely deadly like the Cinder Vortex or Tentacular Darkness. They tend to be slow moving and unintelligent things so if a traveler sees one they may be able to avoid or outrun it. Some have been known to move quickly and a handful display a surprising amount of a low cunning.
Living Spells are treated as Swarms with a few new traits. Pick a base swarm that matches the feel of your spell and modify it with the elements below. Living Spells deal half damage from all attacks and their spells become half as effective when they’re reduced to 50% of their maximum health.
Size: Varies depending on spell but generally the higher a spell’s level the larger the Living Spell. Most Living Spells are Medium to Large in size. AoE spells tend towards larger Living Spells than their spell level implies and some deadly spells can be deceptively small.
Vulnerabilities: Dispel Magic will suppress a Living Spell for a day.
Resistances: Bludgeoning, Piercing, Slashing.
Damage Immunities: A Living Spell is immune to any type of energy its spells create. Cinder Vortexes are immune to Fire damage for example.
Condition Immunities: charmed, frightened, paralyzed, petrified, prone, restrained, stunned
Caster Level: Equal to the minimum level needed to cast the most potent spell they use. Level 4 spells would have a level 7 caster for example.
Trait: Living Spells use Charisma to cast their spells. They should have a Charisma of 10 + the level of the highest spell they use.
Spell DC: 8 + Proficiency Bonus + Charisma Modifier
Mystic Reach (4-6 Recharge): Short ranged melee attack (Reach 15’) that deals 2d6 base damage and triggers whatever spell makes up the Living Spell on whatever is struck. Spell save to resist the spell itself but not the base damage. Base damage is bludgeoning or matches the energy type of the spells used.
Engulf: The Living Spell, like all swarms, can occupy the same space as another creature regardless of the target creature’s size. Any creature that starts or ends their turn while engulfed by a Living Spell is automatically hit with whatever spell makes up the Living Spell, spell save to resist.
Mystic Recharge: If a Living Spell is the target of any spell that makes it up it is instantly healed to Maximum Hit Points.
Scaling: Use the general CR rules for determining Proficiency Bonus, Health, Base Damage, etc. The higher the intended CR of your Living Spell the more potent the spell that makes it up but use the damage benchmarks in the DMG as a guide when choosing your spell. Since Living Spells are swarms that can be “weakened” you can easily create less powerful versions of spells like Fireball or Lightning Bolt and have them become Living Spells that do less damage than their spell level would indicate.
Multiple Spells: It is common for a Living Spell to have one spell effect for its Mystic Reach and another spell for its Engulf. Magical chaos is a hell of thing and they don’t even have to be similar nor share energy types.
Forbidden Spells: Spells that require a lot of direction from a caster, those that have rare or pricey material components, and utterly devastating spells cannot become Living Spells. A Living Wish or Living Gate are game breaking so don’t make them! General attack spells and condition generating spells are your bread and butter for Living Spells.