I'm having trouble with the Cult Strikes Back setup.
I've got four 10th level PCs, with a 6th level NPC druid companion, and I'm looking at the Second Attack options. The text makes it sound like it should be a big force - it talks about multiple nycaloths and mezzoloths and/or multiple cultists dropping down from the black dragon ... but when I do the calculations, I'm getting a deadly encounter with just one dragonsoul, one mezzoloth, and one nycaloth. One dragonsoul and one adult black dragon gets me a deadly encounter as well. (Whereas the black dragon by itself is merely hard.)
Anyone got any advice?
I'm really struggling with this myself right now...like you say the book makes it seem like there should be a lot of Yugoloth on the board but the encounter building guidelines from the DMG just don't support it. After a couple creatures you already hit the threshold. I've spent a lot of time researching this topic and haven't really found any satisfactory solutions...eventually I decided to go with what 'felt' good rather than made any sort of mathematical sense.
I'm running this encounter tomorrow night so I hope it goes alright - although the adjusted XP value (75,000xp!!!) is greater than 4 X the Deadly threshold I'm still worried it might not be enough:
1 Dragonsoul
6 Dragonwings
1 Nycaloth
3 Mezzoloth
1 Adult Black Dragon
The Party is 4 characters, all level 11:
Vengeance Paladin of Tempus
Dragonborn Sorcerer
Gnome Wizard
Halfling Bard/Rogue
They're returning to Silverymoon after the council of Metallic Dragons to meet up with Thunderspells and go back to Waterdeep for the next council session. Before they went to the Nether mountains to speak with the dragons they'd been hearing about a prominent citizen of Silverymoon that had just died. He was a well-known scholar, adventurer and collector of antiquities. The PCs heard various songs by bards around town and watched a Vistani play about his exploits and heroics. They've also learned his will is going to be read to the public and they're very interested in his collection of antiquities (sound familiar? check out 4e Dungeon Delve, chapter 11). So when they return to Silverymoon they'll learn the will reading is happening and go check it out. The Cult also knows about the will reading, and aided by Red Wizards, they have managed to disrupt the wards protecting the town. The cultists fly in on a black dragon and figure they can attack the gathering, take the antiquities for themselves and cause some mayhem and terror in Silverymoon. They don't know the PCs are there but once the PCs try to stop them they immediately recognize the adventurers Severin put a bounty on and summon their Yugoloth mercenaries to kill the PCs.
Here's what makes it hard for the group:
-The cultists will have fire resistance. The wizard and sorcerer are fond of their fire spells
-No one has any magic weapons (the Council requested the Paladin hand over Hazirawn and traded him a Sun Sword for it and then confiscated it from him when he killed an innocent blacksmith) so the Yugoloths resistances will matter
-The Yugoloths can cast Darkness and have Blindvision - I doubt the mage/sorcerer will have Dispel Magic slotted
-The plaza is crowded with civilians, limiting movement
Here's what makes it easier for the group:
-The dragon is really only doing a fly by, using it's breath weapon and then going elsewhere in town to cause mayhem. Not a main participant in the combat.
-The Yugoloths disengage from battle when being hit for more than 1/2 their remaining hit points. The way the Paladin dishes out pain I'm sure it won't take much before they flee. When they disengage they try to summon an ally but their success rates aren't great. Failing that, they flee the battle entirely.
-Each player character will also control one NPC ally during the fight [3 Silver Knights (Knight), and Thunderspells' apprentice (wizard)]
-Crowds are basically cannon fodder
-The Dragonwings are basically pushovers at this point
So I don't know - part of me thinks the PCs will stomp all over this encounter like they usually do but another part worries I've gone completely mad and made an impossible and unfair encounter. I wish the encounter building in 5e was a lot more straightforward and didn't require quite so much guesswork. And it's really, really inaccurate if this ends up being a fair Deadly encounter.