I'm in the process of creating one of the main villains for my current campaign. It's supposed to be a young girl that was rescued by the party from the clutches of an eeveel necromantic cult that extracts blood, sells bodies etc etc.
In reality, I want the girl to be a humanoid with the Unholy Scion template, discreetly poisoning the party to enmity and driving them to do evil deeds for her sake, all under the guise of an innocent, hurt little girl.
What I currently have and need development on:
Race: Human
Type: Outsider
Template: Unholy Scion (Heroes of Horror, +5 LA)
Level Limitation: -
CR limitation: 15-20. This character is originally intended for an NPC, but I'd like to play it on a high-level campaign f I have the chance.
Book Limitation: None.
Attributes: Rolled 18, 18, 17, 12, 12, 10 for her. Still needs x additional points from Levels, plus +2 Dex, +6 Int, +2 Wis, +4 Cha from the template. Preferably, very high charisma and possibly other spellcasting stat.
Class: Gestalt combos encouraged. Thoughts so far: A combination of Psion and Sorcerer or another major spellcasting class, to end up with Thrallherd+Psion or something similar (ideal thought given that path = GSorPsi5, GThdPsi1, GThdSor rest). If you have a better suggestion of classes, feel free to elaborate. What's mainly required is a character that can lie and get what she wants easily, capable of messing with people's minds.
Alignment: Lawful Good.
...no, not really. Lawful Evil preferably, but any Evil would do.
Special:
1. Please try to keep it secret :P I don't want a random detect evil from the party's cleric to give everything away.
2. If you feel like playing around, Familial Bond gives a mother "thrall", potentially powerful as well. If combined with the Thrallherd, this could be fun.
3. Ability to change her shape (though spells could do that I suppose).
4. You don't have to design the whole thing, I'm mainly asking for suggestions and optimal builds here though any help is welcome.
5. Enjoy yourself, above all.
Thank you very much for your time.
Sticking a level in spy master (Complete Adventurer) gives continuous undetectable alignment. All seven levels lets her fake the results of all divinations.
Sticking a level in disciple of Baalzebul (Book of Vile Darkness) gets you both cha and int to bluff checks.
You could go with the telepath alternative class feature that gives telepathy and take the mindsight feat (Lords of Madness 126).
The prodigy unique ability (Dungeon Master's Guide II 157) is +0 CR and can boost all her charisma skills by 5.
Maybe throw some ranks in use magic device in case she comes in contact with an item that's alignment-sensitive.
You could make her creepy as all heck by giving her the swashbuckler dead level ability. If that's past the level of horror you're comfortable with, you can rework the ability to play on maternal/paternal instincts instead, but have the same result (learning information via bluff).