Balancing Encounters around a very proficient Necromancer

In a game I am a part of there is a player who considers themself a necromancer. They are fully specced and invested around the spell "Animate Dead". They are very effective and efficient at keeping track of, and controlling their minions, often taking a minute or few for their full turn with 7 fielded minions, each with multiple attacks. The problem is that they are really really powerful. Their control/raise limit is well over what it should be for their level (+9 from a mixture of class abilities and feats/traits that raise CL.) This means they have been able to raise anything that we have come across as at least a bloody skeleton, even adding extra template via use of desecrate. They also pair this with an elevated CL Command undead spell, giving them a large swath of minions to use that are hard to permanently kill.

The setting of the campaign has been the deep darklands, and while we are only level 7, they have given raise to 15HD bloody Firey skeletons. Needless to say, these outperform any martial at the same level.

The party is a small group, with 1 other consistent player who is a Rouge/Arcane trickster, (about as well optimized as they can be with a couple boons to make them stronger) and then a guest player every now and then who is less important and not consistent. As a GM it is getting hard to balance encounters because as the opponents scale up, the party does as well, but the characters do not gain extra capability. No one in the party is upset at the level of power they have, as they generally tend to do different rolls then meat-bag front-line. However they still like to feel useful in combat, and if enemies are too scaled up, they cant hurt them easily.

What are some ways to allow for more balanced encounters? The challenge is providing something that can be a threat to creatures of that capability, while still proving to be a threat to the rest of the party. Im not looking to nerf them unless absolutely necessary. The necromancer has his body hidden inside the skeleton of a large creature, strapped, secured, and hidden, while using shadow projection to command and be safer on the battlefield. AOEs can threaten his body, but its hard to justify direct targeting of his body over the skeleton it resides in, which is also quite mobile. Keep in mind, that the necromancer can raise pretty much anything, so after every encounter, they can potentially get stronger, and can at this point raise (7+5CL x2 = 24 x2 from desecrate = 48) a 24 HD creature as a bloody skeleton, or a 12 HD creature as a bloody flaming (or elemental) skeleton. This is at level 7.

How should I set up and execute air battles in my session to avoid easy encounters?

I’m running the Storm King’s Thunder campaign, and we are at the portion where the PCs get an airship to travel around in, the airship is about 1000ft in the air. There are approximately 5-6 lvl 7 PCs, and they have 3 or 4 hard encounters a day. There are two wizards, a warlock, ranger, paladin, blood hunter, sorcerer, and fighter.

For the most part, they have had fun with the different weapons and enemies they have faced; however, I find that one or two spellcasting PCs have been using spells such as mind sliver, polymorph, and hypnotic pattern to defeat more challenging encounters, such as one with a roc and wyvern. They make the creature make saving throws with hypnotic pattern and cause the enemy to fall to its death, and using mind sliver makes it even harder, especially on low wisdom creatures like rocs. Or with the polymorph spell, they cause the enemy to become a fish or chicken and throw it off the edge, and since the damage carries over, it kills the monster. I realize it was legal and made fights funnier, but it does get annoying when it’s happening in almost every fight. Are there any suggestions on how to keep them on track without them making every encounter easy?

I thought of giving the monsters immunity to these effects, but it sounds like a lame excuse for me not being prepared.

How should I set up and execute air battles in my session to avoid easy encounters? [duplicate]

I’m running the Storm King’s Thunder campaign in dnd 5e, and we are at the portion where the PCs get an airship to travel around in. There are approximately 5-6 lvl 7 PCs, and they have 3 or 4 hard encounters a day. There are two wizards, a warlock, ranger, paladin, blood hunter, sorcerer, and fighter.

For the most part, they have had fun with the different weapons and enemies they have faced; however, I find that one or two spellcasting PCs have been using spells such as mind sliver, polymorph, and hypnotic pattern to defeat more challenging encounters, such as one with a roc and wyvern. They make the creature make saving throws with hypnotic pattern and cause the enemy to fall to its death, and using mind sliver makes it even harder, especially on low wisdom creatures like rocs. Or with the polymorph spell, they cause the enemy to become a fish or chicken and throw it off the edge, and since the damage carries over, it kills the monster. I realize it was legal and made fights funnier, but it does get annoying when it’s happening in almost every fight. Are there any suggestions on how to keep them on track without them making every encounter easy?

I thought of giving the monsters immunity to these effects, but it sounds like a lame excuse for me not being prepared.

Which 3rd party D&D nested random encounter resource includes combat/social/treasure/mystery encounters for each type of environment?

I had once found a nested random encounter resource, as in there was a master table to determine the whether the party discovered interesting terrain, combat, mysteries, etc and one could then find associated tables for those encounter types for various environments: arctic, trade road, forest, grassland, underwater…

This book was very similar to Necromancer Games 2003 Mother of All Encounter Tables except as I had stated previously unlike MOAET the book I am looking for includes many different types of possible discoveries to come across whereas MOAET simply lists possible monsters one might find and fight in a particular biome.

I do not remember many of the encounters from this book but one that had stuck out in my mind is one from the arctic table where the party comes across a metallic device generating heat in the snow, as if to imply alien or future technology.

Does anyone know the name of this resource or where to find it?

How do you handle random encounters if the GM isn’t supposed to roll dice?

I’m trying to deal with random encounters in DW. If my players are in a town, and suddenly decide to go into a random building how do I decide if the NPCs in there like the PCs? In D&D I’d just roll for a reaction and take it from there. Here I feel like I need to decide if the NPCs want to get along with PCs, and frankly I’m not sure what the NPCs think.

Sometimes I just think a roll of the die is exactly I want for my NPCs.

How to balance encounters with monster NPCs as party allies? [duplicate]

I DM for a group of three players, and having only three players can be quite limiting in terms of encounter design if I want them to face some more varied (higher CR) adversaries. To allow me more freedom, in the past I have granted one of them the control of an NPC to become an ally of the party, using a monster statblock. I try to vary who gets control of an NPC, so everyone has the same amount of stuff to do, and while I try to make the encounter harder, often the NPC is much stronger that the PCs, and so the encounter ends up being easy!

Essentially, if I want to introduce an NPC monster stat block as an ally to the party, how do CR and ‘effective level’ relate for the purposes of balancing encounters, e.g: to make 3 lvl 6 players ‘as strong as’ a party of 4 lvl 6 players, what CR monster do I need to add as an ally?