So I've come to learn the hard way that a CR 23 creature is absolutely no match for four ECL 20 PCs. I honestly had no idea. I thought it'd at least give them a challenge. Boy, was I ever wrong. So I'm going to advance a few of them with class levels and their own creature HD, and increase the number of monsters in a couple of areas. I'm starting to believe that CR 25-27 is necessary to even attempt to stop these guys.
The treasures that the creatures have for "standard", "double standard", etc, will be given to the creatures themselves. There will be other treasure areas that will accommodate for this, and make up for it as well. If they don't find it, that's their fault.
When you're playing a lvl 20 campaign, I'm not holding your hand. I think that's fair.
All creatures are getting the Maurid template. It adds +1 CR, gives them max hp, changes their skin to a gray, and gives them the maurid subtype. It also gains some immunities. Check out the templates at Crystal Keep for more info.
Also, no ToB recommendations.
First up is the thorciasid. I thought this alone would do them in, and it kind of almost did. If the arcane users hadn't botched their spells, this might have been over very, very quickly, and it would have been destroyed in mere seconds. I hadn't realized that.
And yes, I'm trying to take these guys out. It's a Tome of Horrors style. However, let me know if there's no possible way that a group of 12 lvl 20 characters couldn't touch these guys because of AC being too high, etc.
Advancement will be +4 aberration levels to 33, +2 rage monk levels (that wisdom is too insane not to), +1 lion totem barbarian level (pounce).
New CR = 27. +6d8+72 and +1d12+12 HP, +5 BAB, +2 to Fort and Ref saves, +3 to Will, 8+int (aberration), 4+int x2 (monk), 4+int (barbarian), worth 155k (+4 CHA tome for +2 DC increase; 11000,
worth 45k). Feats (3+2) I'll determine later (MultiAttack and Improved MultiAttack are likely), +1 stat Wis, +1 stat Cha (+1 to DC). New AC is +10 for 53 (Dodge feat variant is +1 permanent). Rage likely won't be used, but it's there just in case. Touch and Flat-Footed AC is -18 and -15.
Others I'm looking at seem to be okay for CR (ie Adamantine Golem), but if they're put together with other creatures, it'll increase their CR anyways. I'm just finding that the PCs were not only able to hit them easily, but damage them with ridiculous amounts of hurt. Even if one of the characters may have cheated with their build.