I went ahead and put together a proposed Shadow Oracle build for Akorian.
The Shadow Mystery gives us Bluff, Knowledge (Dungeoneering), and Stealth as Class skills, so we can get a +3 bonus on those right out of the gate. The Friendless Curse makes Diplomacy a non-option, but with a high Charisma attribute Bluff can still work well for us, especially augmented with the Secret Keeper trait; pretty much all Bluff checks are opposed by a Sense Motive check, so that's another +3 bonus right there.
Living in the Darklands makes Knowledge (Dungeoneering) almost a prerequisite for survival if you ever intend to leave whatever relatively safe community you called home. Stealth is just as important for Darkfolk races, and since the Shadow Mystery gives multiple ways to further enhance it, we might as well lean fully into it. Just about everything down here has Darkvision, at a minimum, so we can't just rely on darkness to hide our presence.
I'm not normally a fan of intentionally taking on additional drawbacks, but the Umbral Unmasking trait is such a perfect fit for a Caligni Shadow Oracle that I couldn't pass on it. Doesn't hurt that it lets us pick up another trait.
I know it might seem a bit counterintuitive to invest so many attribute points into Intelligence when it already has a -2 penalty. We need the skill points, though, and the Friendless Curse adds our Charisma bonus on Sense Motive checks and Will saves against Enchantment effects, so we can get by without putting points in Wisdom without too much regret.
[] Akorian the Caligni Oracle
-[] Alignment: Chaotic Neutral
-[] Favored Class Bonus: +1 Hit Point
-[] Attributes (20-point Buy; +2 DEX, +2 CON, -2 INT): STR 8, DEX 14, CON 14, INT 12, WIS 10, CHA 17
-[] Feat: Improved Initiative
-[] Skills (5 points): +1 Bluff, +1 Knowledge (Dungeoneering), +1 Perception, +1 Spellcraft, +1 Stealth
-[] Drawback:
--[] Umbral Unmasking: The shadow you cast is monstrous. Under normal lighted conditions, this is not hard to observe—but uncommon to notice. Creatures that succeed at a DC 15 Wisdom check notice it plainly (an additional Perception check may be required based on environmental conditions). This telltale sign of wickedness cannot be concealed by misdirection, nondetection, or illusions, except those that also affect shadows (such as invisibility).
-[] Traits:
--[] Reactionary (Combat): You gain a +2 trait bonus on initiative checks.
--[] Secret-Keeper (Faith): You gain a +3 trait bonus on Bluff checks when they are opposed by another's Sense Motive check.
--[] Seeker (Social): You gain a +1 trait bonus on Perception checks, and Perception is always a class skill for you.
-[] Class: Oracle (Shadow Mystery) [Friendless Curse]
--[] Revelation: Stealth Mastery (Ex): You gain Skill Focus (Stealth). At 8th level, you gain Signature Skill (Stealth), even if you don't meet the feat's prerequisites. At 16th level, you gain the hide in plain sight shadowdancer class feature.
-[] Spells:
--[] Orisons: Create Water, Detect Magic, Guidance, Mending
--[] 1st Level: Cure Light Wounds (B), Protection from Evil, Shadow Trap