Seeking Feedback Regarding Urban Savant Build

[Doctor Despair]

Hello, friends. I was recently working on a disguise-focused build, so I thought it would be fun to do an opposites-thing by throwing together a build focused on foiling disguise and learning as much about a target as possible. Urban Savant's flat DC to identify those who are disguised was the most potent identity-detection I'd seen, so I decided to build around accessing it as early as possible (without losing out on the major identity-detection of Mindsight). Thanks to Thurbane for gathering so many useful abilities here to refer to.

With that said, how does it look? Any errors folks can see, or any options I've missed out on? I also included some options at the end that I haven't included in the build, but that I'm not confident about leaving out; what do you think of them?

Spoiler: Archivist Build Stub

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Level	Class	Feats	Class Features	Notes
1	Bardic Sage	Favored, Versatile Spellcaster	Bardic Knowledge (+3), Sage spells to list, bardic music (-2 duration)	Spoiler: Notes Show Written into backstory is membership with the League of Eyes (or similar organization for setting). The character is true neutral, motivated by the pursuit of knowledge for knowledge's sake.
2	Archivist	Scribe Scroll	Dark knowledge (tactics) 3/day, prayer book	Spoiler: Notes Show In pursuit of knowledge, the character takes a level of archivist. This grants access to all divine spells for our spell list, given unlimited downtime, and many powerful forms of divination. Versatile Spellcaster allows us to sacrifice our spell slots to cast these divine spells (albeit inefficiently). Arguably, our bardic knowledge class feature should allow us to cover knowledges we don't have ranks in for the purposes of our Dark Knowledge. Combined with Inspire Courage, we should have fairly effective combat buffs in the early game (if we hit the DC). Collector of Stories should come online here, too, to buff our Dark Knowledge check.
3	Human Paragon	Practiced Spellcaster	Adaptive Learning	Spoiler: Notes Show This is the closest thing to a dead level we have, but all great discoveries require great sacrifice. Practiced Spellcaster will help us retain our arcane caster level in spite of missing progression at levels 2 and 3.
4	Human Paragon	Primary Contact	+1 bard spellcasting (2)	Spoiler: Notes Show The second level of human paragon allows us to progress our spellcasting, and to take primary contact at the appropriate level to get 8 ranks in any class skill associated with our organization (ideally knowledge arcana or sense motive). We can afford a Headband of the Lorebinder here for a +4 to bardic knowledge checks, too.
5	Urban Savant	-	Urban savvy (strengths), +1 bard spellcasting (3)	Spoiler: Notes Show We can enter Urban Savant one level early in this way, whereas normally it would conflict with our next level choice. We get access to a similar ability to Dark Knowledge here that grants knowledge of BAB, AC, combat feats, and special attacks/options, reflecting our arduous hours of study.
6	Mindbender	Mindsight	Telepathy, +1 bard spellcasting (4)	Spoiler: Notes Show In our attempts to understand the world and creatures around us, we gain a level in Mindbender and benefit from Mindsight. This synergizes with our Dark Knowledge and Urban Savvy abilities which only require that we be aware of the creatures, not that we see them. We also gain still more information about them (their type and int score), and an effective way to convey all of our information to our allies (telepathy). Additionally, this allows us to foil most forms of disguise where the creature does not share the same type as the creature it is disguised as. This detection is foiled by not having an int score, six levels of the Slayer prc, or, arguably, not having line of effect (although the last is a bit shaky by RAW as far as I know).
7	Urban Savant	-	Urban empathy, +1 bard spellcasting (5)	Spoiler: Notes Show We are so knowledgeable, people love us! ... at least in cities. In rural areas, folks grumble about ivory towers and remain unimpressed.
8	Urban Savant	-	Continuing education +1 (bardic knowledge +4), +1 bard spellcasting (6)	Spoiler: Notes Show Although it's half what a normal bard would have by now, we advance our bardic knowledge, covering gaps in our studies. We can afford Foxhide Armor for several buffs (among which is Scent a few times per day, foiling many forms of disguise for anyone we've scented before).
9	Urban Savant	Vatic Gaze	Urban savvy (weaknesses), +1 bard spellcasting (7)	Spoiler: Notes Show We learn still more information about creatures (what the highest level spells the character is able to cast are, total HD, DR, saves, and weaknesses). Additionally, we can use detect magic at will, rendering many forms of stealth (such as invisibility) useless, as well as most disguises (as we detect, identify the school of, and spellcraft auras around folks).
10	Urban Savant	-	Eyes of the city (low-light vision), +1 bard spellcasting (8)	Spoiler: Notes Show Somewhat of a dead level, but it is what it is.
11	Sublime Chord	-	Bardic lore (bardic knowledge +5)	Spoiler: Notes Show Time to accelerate our casting! The prc is predicated on seeking knowledge, so it seems fitting, and it progresses our bardic knowledge. This also gives us access to permanent Arcane Sight, allowing us to learn about the strongest spell or SLA a creature has currently available, and whether the target has any SLAs or arcane or divine spellcasting. Disguises are very difficult now without misdirection, nondetection, deep cover (from spymaster or zhentarim spy), or god blooded of vecna active.
12	Urban Savant	Combat Intuition	Continuing education +2 (bardic knowledge +6), +1 chord spellcasting (2)	Spoiler: Notes Show We can now check folks' HD as a free action sense motive check that we can repeat once per round, essentially taking 20 on the check.
13	Urban Savant	-	Urban savvy (methods), +1 chord spellcasting (3)	Spoiler: Notes Show A damage boost for all of our friends.
14	Urban Savant	-	Eyes of the city (pierce deception), +1 chord spellcasting (4)	Spoiler: Notes Show At last, we culminate in the ultimate anti-disguise ability. No matter what abilities a character has to hide its nature, our knowledge cannot be denied; we will become aware by what means they are disguised, and then take appropriate measures to pierce the deception as needed.
15	Paragnostic Apostle	Obscure Lore	Knowledge is power, lore (bardic knowledge +8), +1 chord spellcasting (5)	Spoiler: Notes Show The character, in the pursuit of knowledge, joins the Paragnostic Assembly, and gains Obscure Lore as a result of their new experiences. We also begin to advance our knowledge at an accelerated rate to make up for the book studies we've missed out on in our practical studies on worldly matters. The "Knowledge is Power" abilities are somewhat lackluster by this level, but depending on the our favored spells, we can tailor the class to play to our strengths.
16	Paragnostic Apostle	-	Knowledge is power, lore (bardic knowledge +10), +1 chord spellcasting (6)	Spoiler: Notes Show We get a little more knowledgeable.
17	Paragnostic Apostle	-	Knowledge is power, lore (bardic knowledge +12), +1 chord spellcasting (7)	Spoiler: Notes Show We get a little more knowledgeable.
18	Paragnostic Apostle	Research	Knowledge is power, lore (bardic knowledge +14), +1 chord spellcasting (8)	Spoiler: Notes Show As we take our last level of Paragnostic Apostle for the build, we refine our research skills. This seems like a good way to leverage our high knowledge skills for both plot-purposes or finding high-level, rare, obsucre divine scrolls for our Archivist prayerbook. Not counting attribute-based bonus spells, we now have two level 8 spellslots to burn up with Versatile Spellcaster to cast level 9 divine spells from our prayerbook -- should we be able to find them.
19	Urban Savant	-	Continuing education +3 (bardic knowledge +15), +1 chord spellcasting (9)	Spoiler: Notes Show Having learned all we can from the Assembly, we depart again to learn what we can from practical experiments and travel.
20	Urban Savant	-	Urban savvy (true nature)	Spoiler: Notes Show We end on effectively a dead level, which is sad, but we are eligible for epic progression, which is less sad. A magic circle against any creature we can make knowledge checks against isn't awful, but it's a shame we miss out on better class feature's at the capstone. Level 8 really felt like a better culminating ability, but we don't have time to fit in another 10-level prc to completion. We do, at least, keep our full caster level thanks to Practiced Spellcaster way back when.

Spoiler: Artificer Build Stub

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Level	Class	Feats	Class Features
1	Bardic Sage	Favored, Skill Focus: Use Magic Device	Bardic Knowledge (+3), Sage spells to list, bardic music (-2 duration)
2	Artificer	Scribe Scroll	Artificer knowledge, artisan bonus, disable trap, item creation (crafting/casting scrolls with synergies, masterwork tool, Spelllight Spectacles).
3	Human Paragon	Practiced Spellcaster	Adaptive Learning
4	Human Paragon	Primary Contact	+1 bard spellcasting (2)
5	Urban Savant	-	Urban savvy (strengths), +1 bard spellcasting (3)
6	Mindbender	Mindsight	Telepathy, +1 bard spellcasting (4)
7	Urban Savant	-	Urban empathy, +1 bard spellcasting (5)
8	Urban Savant	-	Continuing education +1 (bardic knowledge +4), +1 bard spellcasting (6)
9	Urban Savant	Vatic Gaze	Urban savvy (weaknesses), +1 bard spellcasting (7)
10	Urban Savant	-	Eyes of the city (low-light vision), +1 bard spellcasting (8)
11	Sublime Chord	-	Bardic lore (bardic knowledge +5)
12	Urban Savant	Combat Intuition	Continuing education +2 (bardic knowledge +6), +1 chord spellcasting (2)
13	Urban Savant	-	Urban savvy (methods), +1 chord spellcasting (3)
14	Urban Savant	-	Eyes of the city (pierce deception), +1 chord spellcasting (4)
15	Paragnostic Apostle	Obscure Lore	Knowledge is power, lore (bardic knowledge +8), +1 chord spellcasting (5)
16	Paragnostic Apostle	-	Knowledge is power, lore (bardic knowledge +10), +1 chord spellcasting (6)
17	Paragnostic Apostle	-	Knowledge is power, lore (bardic knowledge +12), +1 chord spellcasting (7)
18	Paragnostic Apostle	Research	Knowledge is power, lore (bardic knowledge +14), +1 chord spellcasting (8)
19	Urban Savant	-	Continuing education +3 (bardic knowledge +15), +1 chord spellcasting (9)
20	Urban Savant	-	Urban savvy (true nature)

Spoiler: Other Options

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I considered using Arcane Dilitente instead of Paragnostic Apostle, but I thought the bonus on bardic knowledge was both more fitting to the flavor as well as more useful than the limited SLAs the AD offered, although the bonus feat was enticing. That we can't seem to easily fit in a fifth level of AD to get always-on scent was disappointing, too.

I considered the option of using Necropolitan and using Lifesense both for anti-stealth and for more type verification (alive vs undead), but the free-action, repeatable HD-check from Combat Intuition seemed more useful in that regard, as it seems to auto-verify the HD of anyone you can see out of combat as long as it is possible for you to beat their "take 10" bluff check by taking 20 on sense motive. I was also vaguely worried about the RP implications of being undead and having no effective means to hide it... although I also vaguely liked the idea of such a knowledge-based character seeking undeath as a means to immortality to pursue knowledge forever. I'm a little torn on this one. I suppose it also would mean Hide from Undead is more of an issue...

[Venger]

It looks fine. Sublime chord is a powerful class that offers a great deal of versatility. Since you decided not to be undead, I wouldn't worry about mindsight. All it tells them re: disguise is your type, which as a humanoid disguised as other humanoids shouldn't exactly tip your hand. While if they were familiar with the person you were impersonating (should you be impersonating someone and not using a fictitious persona,) and have clocked their int with mindsight, memorized the value, and yours is different, that might be something, but at that point, your gm's just trying to invalidate your gimmick, and if it weren't that, it'd be something else.

What specific questions do you have about this build?

As far as rules go, I believe you're implying you sacrifice bard slots to transmute them into artificer spells? If so, you are not allowed to do this. You sacrifice spells from class A to cast higher level spells from class A. You can't use them to cast spells from class B.

You have a bit of redundancy re: feats. I don't really think vatic gaze is necessary given your other abilities.

[Doctor Despair]

It looks fine. Sublime chord is a powerful class that offers a great deal of versatility. Since you decided not to be undead, I wouldn't worry about mindsight. All it tells them re: disguise is your type, which as a humanoid disguised as other humanoids shouldn't exactly tip your hand.

I was only concerned with publically presenting as an undead creature as that will typically make a lot of folks hostile and leave you vulnerable to folks trying to use Greater Turning / Command / etc.

What specific questions do you have about this build?

I was looking for suggestions for options useful for increasing the power of the build (in or out of combat), or emphasizing the knowledge-focus (either generally, or specifically with regard to assessing creatures). I considered Knowledge Devotion, but it seemed like by the time it would come online, the buffs would be a little obsolete. Paragnostic Apostle likewise fits the fluff of the build, but I'm not sure it's the strongest option for those four levels.

As far as rules go, I believe you're implying you sacrifice bard slots to transmute them into artificer spells? If so, you are not allowed to do this. You sacrifice spells from class A to cast higher level spells from class A. You can't use them to cast spells from class B.

I'm not sure that this is right. The feat reads:

Spoiler: Versatile Spellcaster

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You can use two lower-level spell slots to cast a spell one level higher.

Prerequisite
Ability to spontaneously cast spells,

Benefit
You can use two spell slots of the same level to cast a spell you know that is one level higher. For example, a sorcerer with this feat can expend two 2nd-level spell slots to cast any 3rd-level spell he knows.

You sacrifice two spell slots of the same level; then, you can cast any spell you know that is one level higher. The only requirements seem to be that the two spell slots sacrificed are of the same level, and that you know the spell to be cast (as wizards and archivists do for spells in their spell or prayer book). By RAW, we should be able to convert our bard spell slots into spells in our prayerbook -- however, I think a DM would be well within their rights to houserule it such that the slots and spell to be cast must come from the same spellcasting class progression.

In the event that such a houserule was put in place, I'm not sure the Archivist level would be worth it anymore (just for the minor buffs from Dark Knowledge?), nor am I sure Versatile Spellcaster would still be worth taking. In place of the Archivist level, it might be worth taking a level of Artificer for an alternative, but similar strategy (e.g., pursuing knowledge and crafting scrolls to record our knowledge of new, interesting, or exotic spells); if the DM were averse to using our real caster level in combination with the Artificer spell emulation ability, we could make out alright with a Cloistered Cleric dip, maybe. In place of V.Spellcaster, we could swap in Knowledge Devotion, I suppose, or Skill Focus: UMD/Arcane Mastery, or that and something else in the case of the Cleric dip.

You have a bit of redundancy re: feats. I don't really think vatic gaze is necessary given your other abilities.

There is a little redundancy, although I was more concerned with Combat Intuition than Vatic Gaze. Combat Intuition gives no new information, but allows us to find it out as a free action instead of a move action, and allows us to retry the check. It also makes it an opposed roll, though, and by the level we reach Combat Intuition, I'm not sure we can fail the fixed Urban Savvy roll anyway. Maybe we can swap that out for a metamagic feat, or Knowledge Devotion anyway...

Vatic Gaze gives us a non-magical, non-divination method to determine the strongest spells a target can cast (as well as saving us the cost of permanent detect magic). The highest-spells known mode foils even nondetection. It's partially replicated if we get a permanencied arcane sight, but as a divination, it's much more easily guarded against, right?