Some time ago, a reader asked me to take a look at the alhoon, an undead, spellcasting mind flayer that’s almost a lich but not quite. Instead of becoming effectively immortal, the alhoon lengthens its lifespan through human(oid) sacrifice, tacking on however many years its victim has lived. (It seems to me that the alhoon should get however many years the victim has left, but whatever; I’m not a necromancer.)
Alhoons have a daunting array of features, so strap in—this is going to take a while to analyze. We’ll begin with their ability scores, which, like those of the ordinary mind flayer, are weighted toward the mental end, with Intelligence 19 leading the pack. However, unlike ordinary mind flayers, they also have a very high Constitution, along with proficiency in Constitution saving throws. This, combined with immunity (not resistance!) to physical damage from nonmagical attacks and advantage on saving throws against spells from Magic Resistance means their chief vulnerability is to magic weapons, with spells that require Dexterity saves to avoid damage a distant second. And not just any Dex-save spell: they’re also resistant to cold, lightning and necrotic damage and immune to poison. Fireball OK; lightning bolt bad.
In addition to various intellectual skills, alhoons have proficiency in Perception and Stealth, disposing them toward ambush. Their 120 feet of truesight means they probably know when you’re coming for them, and the first thing an alhoon does when it knows you’re coming is Hide.
The next thing they’ll do, however, is try to size you up. In addition to 120 feet of truesight, they’ve also got 120 feet of telepathy. If you’re coming for them, they want to know why (as if it’s not already obvious), and they want to know how much of a threat you pose. If they have good reason believe they’re outmatched, they may never come out of hiding; they may even flee before you ever encounter them. Their Wisdom is 17—they’re not blinded by arrogance. They fight the fights they can win and avoid the ones they’ll probably lose. When they flee, they take their periapts with them.
Not many player-character spellcasters can go head to head with an alhoon. On top of their Magic Resistance and damage resistances, they’re also immune to being charmed, exhausted, frightened, paralyzed or poisoned. In addition, they possess counterspell, which which they’ll shut down any harmful incoming spell of 4th level or lower.
So what’s left that an alhoon does have reason to fear?
- Pretty much any magic weapon, but especially those that inflict fire, thunder, acid or radiant damage. Paladins, with their smite spells, may be better equipped than anyone else to take on an alhoon.
- Simple restraint. Alhoons can’t be paralyzed, but merely restraining them somehow will confer advantage on incoming attacks. They can also be stunned. Either condition will also negate their advantage on Dexterity saving throws against magic, and there do exist physical, nonmagical means of doing both.
Alhoons have the same innate spellcasting abilities as mind flayers, which come with the same silly drawbacks: the inability to cast dominate monster and levitate at the same time, and the overall inadequacy of dominate monster as a practical form of mind control. Plane shift, however, retains its value as a method of escape. And their learned spellcasting is a whole other ballgame.
At the apex of their spell list are disintegrate and globe of invulnerability. An alhoon won’t lead with either of these, however, because it has only one 6th-level spell slot, and it won’t know at the start of combat which spell to use it on. If a battle is going well for an alhoon, it will use disintegrate to take out a key opponent and consolidate its advantage; if it’s going poorly, globe of invulnerability is its means of buying time. It will usually wait until the third round of combat to make this assessment, though it may do so as early as the second round if the first round makes the situation obvious one way or the other.
A better spell to lead with is wall of force, with which it can shut down an enemy wielding a weapon it fears by dropping an impenetrable bubble over it. Alternatively, it can drop a flat wall to divide its enemy’s forces however it pleases, placing itself on the side with the foes it wants to fight. The alternative 5th-level spell, modify memory, is to be used against prisoners, not combatants.
Between 2nd and 4th level, we have the pool of spells that can use each other’s slots interchangeably. Invisibility is always useful (unless the alhoon is sustaining wall of force or some other concentration-required spell), scorching ray is worth boosting, lightning bolt is a good way to mock opponents who can’t effectively do the same back, and Evard’s black tentacles is a good way to hold four or more enemies down while pelting them with scorching ray and lightning bolt. But the star of this show is counterspell. An alhoon will never use its last 3rd- or 4th-level slot on anything else as long as its enemies include a spellcaster powerful enough to ram damage through its Magic Resistance. And then there’s mirror image, which is cheap and has no downside except its opportunity cost. If the alhoon can afford to wait a round before casting wall of force, it may as well cast mirror image as its opening play, because that affords it a measure of protection against opponents wielding magic weapons.
Next, we have the 1st-level workhorse spells. Detect magic has no application, and disguise self is what the alhoon uses beforehand to keep combat from breaking out in the first place. (Note that disguise self doesn’t allow an alhoon to speak a language it doesn’t know, and telepathy can’t be mistaken for ordinary speech. This spell is better for hiding in anonymous crowds than for impersonating a non-alhoon-type individual.) Magic missile isn’t quite as good as scorching ray. Shield, however, is a reflex action familiar to every arcane spellcaster, an automatic reaction against any attack roll of 15 to 19—unless the alhoon has reason to fear an incoming spell more than a blow from a magic weapon, in which case it has to eat the damage and save its reaction for counterspell. Because of its high Constitution and fairly generous number of hit points, it can often afford to make this sacrifice. But while a blow from a +1 longsword is small potatoes, a blow from a weapon that stacks another type of damage on top of the regular bludgeoning, piercing or slashing, to which the alhoon is susceptible, is one that the alhoon has to seriously consider casting shield to repel. Remember, the alhoon has Magic Resistance; it has no resistance to a melee weapon attack with a flame tongue sword.
Finally, cantrips. Because the alhoon is a 12th-level spellcaster, chill touch and shocking grasp, which do 3d8 necrotic and 3d8 lightning damage respectively, plus other potential effects, are actually better than the alhoon’s Chilling Grasp action, which does only 3d6 cold damage and has no additional effect. Granted, most opponents who get right up in an alhoon’s face will be mid- to high-level fighting classes or rogues, and that means either Extra Attack (multiple attacks per round) or Sneak Attack (4d6 or 5d6), compared with which a single attack for 3d6 or even 3d8 damage doesn’t look all that impressive. At best, Chilling Grasp is the alhoon’s way of showing its disdain for a melee opponent who didn’t realize his or her mundane weapon wasn’t going to do anything to the alhoon, and for this purpose, shocking grasp is superior. (Chill touch, which does 3d8 necrotic damage and keeps the opponent from being healed, is a ranged attack, so an alhoon casting it at point-blank range would have disadvantage on the roll. The range, however, is a generous 120 feet, making it a potential finishing move against a fleeing opponent.)
Last, there’s Mind Blast, the illithids’ stock-in-trade. While the alhoon doesn’t want to use it unless it can catch at least six of its opponents in the 60-foot cone (or all of its opponents, if there are fewer than six), it targets an ability that many PCs use as a borderline dump stat, does respectable damage and imposes the stunned condition on a failed save, giving the alhoon advantage on its spell attacks and the target disadvantage on saves against Evard’s black tentacles.
Here’s the alhoon’s overall strategy:
- First, from hiding, use Mind Blast if the minimum criterion (six opponents, or all opponents if fewer than six, in the area of effect) is met. Mind Blast is neither an attack nor a spell, so the position of a hidden alhoon is not given away by this action. That means it can follow up with, say, a scorching ray with advantage on the attack roll on the next round.
- Once its position is given away, use mirror image and/or wall of force to forestall any attack that might actually hurt.
- If it hasn’t already used Mind Blast, or if it’s already recharged, position oneself optimally and let ’em have it. Do this anytime Mind Blast is recharged and it’s possible to meet the positioning criterion.
- Use Evard’s black tentacles to hold as many opponents as possible in place (minimum four, unless there are only three opponents), then pelt them with scorching ray, boosted to 3rd or (preferably) 4th level if a slot is available—but always keeping one of each in reserve for counterspell. (Note that Evard’s requires concentration—as does wall of force. Cast Evard’s only if wall of force is no longer needed.)
- Cast shield as a reaction to deflect attacks with magic weapons more powerful than a straight +1 to attack and damage (unless all they add is cold, lightning or necrotic damage, against which the alhoon has resistance) when the attacker rolls 15–19.
- Cast counterspell as a reaction to ward off harmful spells if the alhoon has already failed one saving throw against magic, which suggests a particularly powerful enemy spellcaster.
- Use shocking grasp (rather than Chilling Grasp) against melee attackers who’ve bitten off more than they’ve realized they can chew.
- If all nearby opponents are effectively neutralized, use chill touch to pick off any opponent who’s fleeing.
- If the battle has swung decidedly in the alhoon’s favor, take out a key enemy with disintegrate. If the battle has swung decidedly against the alhoon because the opposition has better spellcasters, substitute globe of invulnerability for wall of force.
- The alhoon’s primary positioning consideration is how to catch the most opponents in the areas of effect of its spells and Mind Blast. Engaging with, or disengaging from, a specific opponent or opponents is secondary.
Alhoons have a strong self-preservation impulse and will flee, or at least withdraw, after taking moderate-to-serious damage (reduced to between 49 and 72 hp), using the Dodge or Disengage action if they have allies on the field and the Dash action if they’re alone. Whether they choose to Dodge or Disengage depends on how many melee opponents they’re engaged with: if more than one, Disengage, otherwise, Dodge. If they’re seriously wounded (reduced to 48 hp or fewer), they plane shift out of there.
Next: death knights.