Lion's Tactical Guide to Phaerimm

Phaerimms are another creature from previous editions of the game that have been alluded to in 5e’s lore before (in this case, within the flavor text description of Icewind Dale: Rime of the Frostmaiden’s grotesque tomb tapper constructs), but only given a stat block now, and only in a book that very few are likely to have heard of. These highly intelligent funnel-shaped aberrations with rows and rows of teeth dwelled in the Underdark and posed a particular problem for the ancient Netherese of 5e’s Forgotten Realms setting due to their evil magic draining the vitality from the world, which is why they designed the aforementioned tomb tappers specifically to go out into the Underdark and exterminate them alongside other threats such as the mind flayers. They were nearly successful in this endeavor, but a handful of phaerimm survived and are now motivated primarily by their desire to rebuild their population. Of course, with each phaerimm only being able to produce one egg every century, this is naturally going to take a while, so phaerimms spend most of their time consolidating their holdings in the Underdark and living relatively solitary lives with no one but their mind-controlled slaves and the occasional other phaerimm for company, whom they only band together with out of necessity to defeat a stronger foe.

Stronger foes are hard to come by, though, because at CR 15, even a single phaerimm is one tough customer whom even high-level parties may have trouble against. Although somewhat sparse on hit points for their CR (the CR 15 theoretical average of 288 is exactly double what they have), their deadly array of physical attacks combined with their massive pool of available spells to cast make them incredibly formidable foes. Their physical ability scores are nothing to sneeze at, with the exception of their merely above-average Dexterity compared to their excellent Strength and Constitution, but their mental ability scores are equally impressive, with their exceptional Charisma serving as the power source for their spellcasting repertoire (they could use it for parley, but their language is stated as being incomprehensible to humanoids, plus that just isn’t how they roll), followed by excellent Wisdom and Intelligence that allows them to easily gauge their opponents’ weaknesses. They have proficiency in Intelligence and Charisma saves along with Arcana and Insight, helping them to figure out what their adversaries will do, but aside from nonmagical weapon resistance and immunity to the petrified condition, they don’t have much compensating for their lower hit points. They have 120 feet of truesight, telepathy out to 100 feet (which they mostly use to speak through their minions), and can hover through the air at a speed of 30 feet compared to their dismal 15 feet walking speed. Their Immutable Form trait prevents them from being polymorphed and the like, while their Magic Resistance leaves them even more well-equipped to handle spellcasters, although spells that force Dexterity saves are bound to mess them up more often than not. Another trait that helps them take on spellcasters is Arcane Sight, allowing them to detect magical auras and any spellcasters present within 60 feet of them, although their lack of access to Dispel Magic makes it so they don’t have many ways to take advantage of this information beyond knowing who to target. The standout trait of theirs, however, is Extended Concentration, which allows them to concentrate on two spells at once, at the risk of losing both should their concentration check fail. This trait, although incredibly potent, also makes it even more difficult to analyze their spells than it otherwise would be, so let’s go ahead and take a look at all of that, going down from the highest level to the lowest level:

• Dominate Monster is, as has been discussed on this blog before, somewhat weak as a capstone spell, but potentially more useful in the current D&D landscape than it was before given how several player races are now creature types other than Humanoid, making them immune to the Dominate Person spells that the phaerimm also has access to. Still, unless such a target is vastly more useful to them than any of their humanoid allies, or there’s a big monster that you want the phaerimm to be controlling as a minion, then it probably won’t have much use for this spell and could potentially even leave the slot open to upcast another spell in its repertoire that I’ll get into in a moment.

• Prismatic Spray is a powerful AoE spell that afflicts each creature in a 60 foot cone with one of seven different effects on a failed Dexterity saving throw (or two if 8 happens to be that creature’s unlucky number). The first five are simply a flat beam of 10d6 damage: fire, acid, lightning, poison, and cold. The sixth is a restraining beam that permanently petrifies on an additional three failed Constitution saves or frees the target on three successful Constitution saves, more useful for keeping a single target down than actually dealing any long-term harm. Finally, the seventh is a blinding beam that forces an additional Wisdom saving throw, ending the blindness on a success or permanently banishing them to another plane on a failed save, usually the Astral or Ethereal Plane if the target creature is on their plane of origin, and on their plane of origin if they aren’t. Ultimately, since there’s only a 12.5% chance of a single target getting hit with two rays, the phaerimm isn’t going to drop this until they can get all of their enemies within the area or until they can get six of them, whichever comes first. They’ve only got one shot with this thing, so they’re gonna make it count.

• Reverse Gravity is perfect if the phaerimm’s lair happens to have a ceiling higher than 100 feet, since any targets that fail a Dexterity saving throw to anchor themselves on to something will be sent flying upwards towards it, then float there oscillating at the 100 foot mark until the spell ends and they fall back down, taking 10d6 bludgeoning damage from the impact. Being a 50-foot radius cylinder, the phaerimm can reasonably expect to catch up to 10 creatures in it, accounting for all of their enemies and then some unless they’re especially spread out. This spell is pretty much the best means the phaerimm has at effectively locking down a group of active combatants not likely to get caught up by their charming shenanigans, allowing them to pick out a character from the lineup to isolate from their group and target as the chosen host for their egg. What’s more, as soon as the spell has served its purpose, the phaerimm can drop concentration on it as a free action, giving them free damage before piling on the pain with another spell. Of course, keep in mind that they’ve only got one use of this thing, and that using it effectively bars them from using Prismatic Spray unless they burn their 8th level slot on it, which has no benefit due to Prismatic Spray not scaling with level.

• Chain Lightning is a solid backup AoE for the phaerimm to use against a clustered group of enemies, targeting up to four creatures with 10d8 lightning damage on a failed Dexterity saving throw or half as much on a success, provided that the last three are within 30 feet of the first one. What’s more, unlike Prismatic Spray, this one can be upcast, firing off an additional lightning bolt to another target near the first one for each spell slot level above 6th. Although upcasting this to 7th level isn’t worth it because of the phaerimm’s 7th level spells competing for the slot, upcasting this to 8th level might be worth it if there’s no compelling reason for the phaerimm to cast Dominate Monster, hitting up to six creatures in a 30 foot radius around the first creature. For this reason, I’d say the phaerimm jumps at the chance to upcast this if six of their enemies move close enough together for them to pull this off and there’s no reason for them to use Dominate Monster, but they will settle for casting the spell normally if no such opportunity arises.

• Mass Suggestion is the phaerimm’s go-to means of mass mind control, although it’s more limited than the Dominate Person and Dominate Monster spells in terms of just how much sway the phaerimm has over their targets. This spell could easily be used to represent the phaerimm’s control over their rank-and-file minions, but it could also be used by the phaerimm to try and get the party to leave them alone, since being in combat with the casting creature does not give the targets advantage on their Wisdom saves. Another neat thing about this spell is that it can be upcasted, increasing the duration of a given suggestion to 10 days with a 7th level spell slot or 30 days with an 8th level spell slot. This means that, provided they are willing to go without an 8th level spell slot every so often, the phaerimm can potentially hold dozens of minions under their carefully-worded power indefinitely. Mind flayers, eat your brains out.

• Telekinesis is good for restraining a single foe and keeping them from doing anything, but the phaerimm has easier means of taking a foe out of the fight. This spell is better used as either an offensive weapon, lifting heavy boulders and the like to crush their foes or cut off exit tunnels from their lair, or as a simple means of convenience, using it to take away an incapacitated humanoid as they leave to implant them with their egg (sure, they could just pick them up with their hands, but that’s a task for “the help,” not them).

• Hold Monster isn’t quite as useful to the phaerimm as Hold Person would have been, even with the newly non-humanoid player races that wouldn’t be affected by Hold Person. They could still conceivably upcast it to 8th level and paralyze four foes at once, provided that they are within 30 feet of each other, but in comparison to upcasting Chain Lightning to 8th level at six targets, though, there’s not much of a contest. Besides, as mentioned before, the phaerimm has easier means of taking a foe out of combat.

• Dominate Person is the phaerimm’s go-to mind control spell for a single target, although their ability to concentrate on two different spells seems to preclude doubling up on Dominate Person with two targets. Still, it’s definitely useful to have running alongside another concentration spell, leaving the party fighting on multiple fronts between the phaerimm themselves, the phaerimm’s minions, and one of their own allies. Although the spell can be upcast, all upcasting does is increase the spell’s maximum duration, which doesn’t really change much given how short combat tends to be in 5e.

• Phantasmal Killer is a pretty sub-par source of damage compared to some of the phaerimm’s other spells, and unlike the dread doppelganger, the phaerimm doesn’t really have anything going for it that makes this spell more useful aside from the ability to concentrate on another, better concentration spell, an ability which they can just as easily utilize to concentrate on two better concentration spells.

• Greater Invisibility is one of the phaerimm’s favorite spells, an excellent defensive spell made even better by the phaerimm’s ability to run another concentration spell alongside it. If the phaerimm is expecting intruders to come barging in, they will make sure to cast this spell before they show up, and if they aren’t, they’ll still use it in the very first round unless something better comes up. Disadvantage on incoming attacks and advantage on attacks against their foes, as well as not being able to be targeted by many spells, makes this too great a buff to pass over unless there’s a really compelling reason to do so.

• Confusion is a good means of sowing mayhem in the ranks of the phaerimm’s foes, although the randomness of its effects makes it a little tricky to truly capitalize on. Still, it’s a good spell to throw up before retreating to frustrate pursuit, although Reverse Gravity would probably be better for this purpose if it’s still available.

• Hypnotic Pattern is another good means of locking opponents down in a group, prohibiting the phaerimm from dealing additional damage to those targets, but doing a better job in that role than upcasting Hold Monster. This is also a good alternative to Confusion when it comes to frustrating pursuit once the phaerimm decides to flee.

• Fear is a good spell for when the phaerimm wants to get a group of adventurers out of their lair and Mass Suggestion didn’t quite do the trick. This is also another spell which the phaerimm could use to frustrate pursuit or separate a single potential host from their group by scaring them into abandoning their friend.

• Fireball is useful in the same situations that Chain Lightning is useful, although the phaerimm will likely save it for after they’ve run out of chances to use Chain Lightning unless they realize that fire damage is more effective against their foes for some reason. They can afford to upcast the spell to fourth level once, given the general uselessness of Phantasmal Killer, but otherwise they’ll cast it at third level.

• Phantasmal Force is a decent means of locking down a single opponent by locking them in a phantasmal object such as an iron maiden, making the target believe that they’re trapped while also wearing them down with psychic damage over time. It also helps that the phaerimm doesn’t have as much to worry about as far as competition for concentration slots goes when compared to other spellcasting monsters. Still, there are probably better means available to them to lock down their foes.

• Detect Thoughts is more useful for out-of-combat social engagement, but between the phaerimm’s high Insight and their ability to gather information from a creature they have charmed using Dominate Person or Dominate Monster, there isn’t much that this spell can offer the phaerimm that they can’t get through other methods.

• Crown of Madness is a generally inferior mind control spell compared to the others available to the phaerimm; once they’re pushed to using this, it’s long past time to leave.

• Shield is an excellent means of avoiding damage for the phaerimm to make use of, jacking their standard AC of 18 up to 23 for a brief period. They make use of it liberally whenever their foes are on the verge of getting them with an attack or a massively upcasted Magic Missile spell (such as from a Wand of Magic Missiles being fully unloaded), and may even use a second level slot for it if they run out of first level slots.

• Magic Missile is a generally inferior damaging spell compared to the others at the phaerimm’s disposal, particularly since their +11 to hit with spell attack rolls and +10 to hit with their melee attacks leaves them fairly unlikely to miss.

• Dissonant Whispers is a much better low-level damaging spell for the phaerimm to use, since it not only deals good psychic damage, but also can force an opponent in melee with the phaerimm to run if they fail a Wisdom saving throw, allowing the phaerimm to make a Stinger attack against them once they move beyond 10 feet. They’re willing to upcast it to second level once if they believe the extra damage will make the difference.

• Of their cantrips, Mage Hand and Minor Illusion have limited utility while Poison Spray is likely to be resisted or saved against. Ray of Frost is far and away their best cantrip, dealing about as much damage as Dissonant Whispers on an attack roll which they can easily give themselves advantage on with Greater Invisibility, while at the same time reducing their target’s movement speed on a hit.

Whew! Now that that’s done with, let’s go over their other actions. They have a Multiattack which allows two possible options: four Claw attacks and a Bite or Stinger attack, or two Claw attacks and casting a single spell. Regarding the first option, Stinger is far and away a better option compared to Bite, since both the Claw and Stinger attacks have a ten foot reach compared to the Bite’s five foot reach, and although the Bite does a smidge more damage than the Stinger, the Stinger inflicts paralysis on a failed DC 18 Constitution saving throw. Curiously, this paralysis effect has a unique rider: the paralyzed target floats five feet from where they were struck. This doesn’t really affect much except for one possible situation: the phaerimm making a Stinger attack to paralyze a creature held up in the ceiling by Reverse Gravity before dropping the spell afterwards, isolating their target from their falling allies and punishing them for breaking out of the paralysis with a hundred foot drop. Regardless, in the case of the first Multiattack option, the phaerimm makes their Stinger attack in hopes of paralyzing their foe, then concentrates all four Claw attacks on that paralyzed foe in order to take them out fast with four auto-crits. In the case of the second Multiattack option, the phaerimm casts their spell of choice first, using the guidelines I’ve gone over above, then makes use of their two Claw attacks to take advantage of any opportunities to deal more damage that were created by the spell they just cast. With how many spells the phaerimm has at their disposal, I would say the phaerimm opts for the second Multiattack option more often than not. The only case in which the first one is preferred is when the phaerimm wishes to set up their Implant action, which consists of making a single Stinger attack against a paralyzed target in order to implant their egg into the host. Since the phaerimm only has one of these eggs every century, they have to be incredibly judicious when making use of this attack, and probably won’t even take the risk of using it until everyone but their chosen host is dead. As for that chosen host, they will specifically make sure that their host isn’t a spellcaster with access to any magic that cures disease, as that will kill their egg before it can fully develop into its larval form. Although they’re smart enough to know which classes have access to such magic, they’ll probably target a non-spellcaster for this purpose to be on the safe side, just in case said host had a scroll with one of those spells on it on their person when they were abducted. Since the paralysis from their Stinger attack only lasts for up to a minute, the phaerimm will make sure to keep their target unconscious long enough to regain access to their various mind control spells so that they can keep them under their power for the ninety day incubation period of their egg. Once that time has elapsed, the larva bursts out of the host’s body and kills them, ready to begin their life as a tiny underground tyrant.

Taking all of this together, the phaerimm makes sure to bring out the big guns early and often in dealing with invaders, knowing that they aren’t likely to last long enough to even make use of all of their higher level spells. If they have advance warning, they’ll cast Greater Invisibility before the intruders arrive; if not, this will be the first spell they cast on themselves unless they have a better option to use right off the bat. As their mind-controlled minions run interference, the phaerimm makes sure to pick their battles carefully. If they’re looking to implant a host, they’ll focus their attacks on the best candidate for that purpose, but make sure to leave them alive for later implantation. If they don’t have an egg in them, however, they stay out of melee combat with any target that could actually hurt them, focusing on battering their foes with their spellcasting in order to wipe them out as quickly as possible while making their two Claw attacks against spellcasters to pile on the damage. 

Having only narrowly survived the complete extinction of their entire species, phaerimm have an extremely sensitive survival instinct, and will move to flee a combat encounter as soon as they are moderately wounded (reduced to 100 hit points or less), leaving any surviving minions to run interference. If they’ve managed to paralyze someone with a Stinger attack and seek to implant a host, they will use Telekinesis to drag their victim away along with them, using some of the lower-level spells I went over above to deter pursuit. If they weren’t seeking to implant a host to begin with, however, they will cast Greater Invisibility if they haven’t already and use their deterrent spells as they float away.