Pathfinder games are notorious for difficulty spikes in some areas but a solution might be fairly simple at times. One such example is a particularly annoying Nalfeshnee.
Pathfinder: Wrath of the Righteous may have thrown a Nalfeshnee at you before but it's possible you beat it with relative ease and didn't pay much attention to this particular enemy. After venturing into a certain lab upon acquiring the Azata Mythic Path, your opinion about this demon may change from irrelevant to incredibly annoying. If you are looking for general tips about the Nalfeshnee, we should warn you that the guide might contain some spoilers in the text below.
Nalfeshnee's in Areelu's lab is more annoying than usual for a few reasons - it's hard to hit, the battle happens in a tight space and it has a Vrock friend nearby. All of this can prove overwhelming and you are probably going to end up with Death's Door on several characters, lose them or get your entire party wiped as a result. The worst part is you don't even know what happened or how to overcome it.
Lab Nalfeshnee strategy
Assuming you reached this part of WotR without having to savescum at every corner, it's safe to guess you have a somewhat competent party. Still, they will miss the creature a lot and crowd control is bound to overwhelm them after a fairly short period of time. In other words, this is a DPS race, much like the ones seen in WoW raids - you either kill the creature before it enrages or you get wiped.
In the case of Nalfeshnee, it doesn't exactly enrage to deal obscene amounts of damage. When your time runs out, it will have used Unholy Nimbus three times and your entire party is stunned for a month, at which point it will just pick them off. To counter this, you can sacrifice one character - make it provoke the demon into stacking the Nimbus but the party member's fate is sealed at that point - chances of them surviving are slim to none.
If you want to keep your party intact, you will need to rely on the oldest trick in the Pathfinder book - buff up to your eyeballs. Bless, Prayer and Haste are the best AoE buffs you can count on.
Single target buffs are extremely potent too - Magic Weapon and preferably Greater Magic Weapon will increase the target character's Attack score, giving you a better chance to go through the demon's high AC. Instrument of Freedom, the ability your main character gets from the Azata Mythic Path, can be used in a similar way and it will help against Vrock and Nalfeshnee's debilitating effects.
The Nalfeshnee will also keep buffing itself so throw a spanner in its worth by debuffing the thing. Bane and Evil Eye (AC) are particularly good. Using Evil Eye might be a bit tedious since Nalfeshnee will most likely succeed in all the saving throws, meaning you have to recast the Hex each round but dropping its AC is well worth the inconvenience. Any type of Smite you have on hand is of great help too.
Teamwork feats work well too, especially Outflank. If you have a Cavalier or Fighter in your party, the character can bestow this feat on all allies who don't have it and stacking melee units against the Nalfeshnee can have a better chance of penetrating its defences. Keep in mind that the Fighter needs special weapon training in order to extend the benefits of Outflank to allies.
With the tips from the strategy part of this guide, it's pretty straightforward - first, use all of the buffs that are available before you enter the fight. Use the tactical pause to queue up each round of the buffs to avoid losing precious time on them.
After that, you should zerg the Vrock first. If your characters fail their saving throws, it will stun them temporarily, buying the time for the Nalfeshnee to buff up and stun everyone forever. Kill the Vrock before it gets the chance to do so.
While your main damage dealers are killing the Vrock, use the support characters to summon any creatures they can. These will serve as cannon fodder in case the Nalfeshnee gets to attack something.
When you turn your attention to the Nalfeshnee, make sure all of your characters are in a position to be able to attack the creature - a single damaging blow that doesn't happen could result in a stunning disaster.
Overall, the objective is to have your party members' Attack as high as possible and Nalfeshnee's AC debuffed globally or in a situational manner. This will allow you to kill it just before it gets the last bit of Unholy Nimbus off and move on with your crusading.