Originally Posted by pyromanser244
the target CR is 20. that might change but modding an existing build should be easier than starting from scratch. and I'd have to say that ur-priest is associated, even if the fiend is built for something else both the power level and story agree that the PrC is at the heart of this characters power.
I do want to have the ur-priest be the star of the show, it's kinda the foundation of the character idea. that being said, I'd be lying if I said I hadn't considered using theurge to add some arcane. there are even story reasons to justify it.
truth be told I'm still torn between pure ur-priest and theurge.
I'm not worried about melee though. most fiends are already competent melee fighters and this guy will have access to cleric buffs so he should be good enough on that front. could even have V vs. Black Dragon type encounters, but this route would be a tertiary concern.
While your logic on associated vs. nonassociated misses a bit of the central point (it doesn't matter what the final capabilities are, what matters is how much the initial fiend helps or hinders those capabilities: basically, levels are treated as nonassociated so a character can "catch up" to a level that goes with its CR), I agree with your conclusion, so let's get to building!
Your goal is CR 20, which means with associated levels we're looking at something up to CR 10 for the base fiend. Outsiders get all good saves, so you don't need to worry about the base save requirements, you'll have them covered. In terms of skills, you'll probably have enough skill points if your Int isn't too low. Without Knowlege(religion) and Spellcraft in-class you need 13 RHD, while if you have those two it lowers to 9 if you're lacking Bluff, or 7 if you're lacking arcana or the planes.
I'll focus on demons, though I'll also mention other cool dudes as they arise.
Succubus is an interesting option, though the lack of Spellcraft means you'd need a few levels in something with it as a class skill. If you're going theurge though that could be a good choice, and Succubi do have lots of Cha for fueling DMM.
Vrocks have both all Knowledges and Spellcraft, as well as enough HD that you can buy Bluff cross-class. They're one point of CR under the limit, so you've got room for one more level of something else. Fairly good though not stellar mental ability scores, and some nice SLAs.
Palrethees (MM2) get the right skills and the right attitude, but their mental ability scores aren't stellar and their SLAs are just sad.
Zovvuts (MM2) would need to dip to get the Knowledge, but you do have a level to spare for that, if only one, which might make points tight. Decent mentals, decent SLAs, and a create spawn ability
Maurezhi (FF) are kind of interesting due to shapeshifting abilities, but you need to get enough ranks in Knowledges and Spellcraft from a one level dip, which might not be fun, especially with a racial Int penalty. Plus, low HD. (Note CR of these guys was waay downgraded in FCI, so might be a better choice actually).
Arrow Demon (MM3) might be fun for a Zen Archery character, but you'd need to dip for the skills. Got a few levels in which to do it though.
Nycaloths (MM3) are yugoloths, not demons...but they do get almost all the right skills and have enough HD (14) to buy the rest cross-class. They come in right at CR 10, with ok but not great mental scores and mostly mediocre SLAs (though at least greater teleport at-will).
Mezzoloths (MM3) are wimpier on that front, but you have more levels to play with in between if you want.
Adaru (MM5) makes for a good leader-demon, had the HD and Int to buy relevant skills cross-class, and is a goddamn giant centipede. Not too many SLAs, but gets the job done.
I really like the idea of using a Bar-lgura (FCI), but purely for the gorilla-grodd image. They've got some fun SLAs, but aren't really an amazing choice, and take a lot of levels to get to where you want them.
A Dybbuk (FCI) is sort of a weird choice, and takes a dip to get the right skills, but if you want an incorporeal guy who possesses corpses this does it for you.
Ekolid (FCI) would be a very different choice. Low CR, so room for enough dips to get the right skills. You're a bug from before the dawn of man who spreads madness in your wake.
Yochol (FCI) would be almost ideal, but the idea of one rejecting Lolth is pretty much impossible.