Here's what I have for Siduri's level up and retraining. It keeps her Enchantment focus, while going even further in that direction. The Master Specialist PRC gives her some neat stuff, including a couple bonus feats and Enchantment-related abilities. Mindbender is there solely for the Telepathy, which allows her to learn the Mindsight feat for the mental radar effect.
She keeps her Social Proficiency ACF in order to gain various social skills as Class skills. This fits her character and makes it much easier to qualify for Mindbender. Eidetic Spellcaster is something should could have easily had before now and we just never had on screen reason to see it mentioned. I figure that in the school where she learned magic (Academy of Chains, IIRC) in Dis, having spellbooks were a critical weakness which could all too easily be exploited by fellow classmates and staff, and a having a Familiar would just be asking for trouble there, since it would probably have to be an Imp and those are untrustworthy at the best of times. Evil Hogwarts in Hell isn't the place you want to have an Imp Familiar. Trading the ability to bond a Familiar and to Scribe Scrolls for not needing a spellbook would be understandable.
The only feat she loses from her previous build is Persuasive in order to gain Mindsight. Losing the +2 bonus to Bluff and Intimidate is a decent trade-off, IMO. She keeps Diversified Casting (Abjuration), but the spells are getting updated; Greater Dispel Magic over Dispel Magic and Break Enchantment for obvious reasons, Life Bubble for the pure utility of being able to protect herself and a dozen or more other people from all sorts of harmful environmental conditions that could be encountered on the Plane of Fire or elsewhere, and Ward Shield as a solid defensive buff for herself or an ally (once we get her a Mithral Buckler to wear).
Her skills are mostly staying the same, though Bluff and Diplomacy had to be reduced in order to fit in ranks Sense Motive. Upon further thought and input from ya'll, Diplomacy feels like the social skill she can most afford to reduce, while Intimidate and Sense Motive would be most important and fitting. Bluff isn't hurting too badly, however, and her Beguiling Liar racial ability helps there, too. She can also augment her socials with the standard spells (AoN, VotD, etc).
Ya'll have any thoughts or suggestions for additional changes?
EDIT:
Crap, just noticed that the Commanding feat requires Persuasive as a prerequisite feat. Lemme see what I can do to fix this without losing Mindsight. Crisis averted,
Shadow Magic acquired. Teana and the Myrkdreki benefits from it for their Shadow spells, but it would be just as advantageous for Siduri's Enchantment spells, and given her heritage, background, and schooling, it's not far-fetched that she could have learned it over the centuries.
[] Siduri Rebuild + Level Up
-[] Classes: Wizard (Enchantress) 5/Master Specialist (Enchantress) 7/Mindbender 1
--[] Prohibited Schools: Abjuration & Evocation
--[] Alternate Class Features:
---[] Eidetic Spellcaster: You do not need a spellbook, either to record spells you know or to prepare known spells. You do not gain the ability to bond to a Familiar or the Scribe Scroll bonus feat.
---[] High Specialist (Enchantment): You gain Social Proficiency (Bluff, Diplomacy, Gather Information, Intimidate, and Sense Motive as Class skills). You do not gain bonus feats for advancing as a Wizard.
-[] Feats: Diversified Casting (Abjuration), Greater Spell Focus (Enchantment)(B), Mindsight, Potent Enchantment, Shadow Magic, Skill Focus (Spellcraft)(B), Spell Focus (Enchantment), Spellcasting Prodigy
--[] Diversified Casting: Greater Dispel Magic, Life Bubble, Ward Shield
-[] Flaws: Noncombatant
-[] Skills (91 points): 10 Bluff, 15 Concentration, 4 Diplomacy, 15 Intimidate, 10 Knowledge (Arcana), 10 Knowledge (The Planes), 15 Sense Motive, 10 Spellcraft
--[] Skill Trick (-2 points): Swift Concentration
-[] Spells:
--[] 7th Level: Mass Demanding Message, Stun Ray