Summary:
Name: Sophia Schulp
Title: Emissary of the Depth, multiple doctorates
Age: chronologically in her forties, biologically ca. 30
Species/nationality: German transhuman
Gender/sexual orientation: Female/asexual
Powers: Superhuman intelligence, various minor cognition powers, nearly indestructible head, "cult" of swashbucklers
Occupation: Universal genius, trickster

Alignment: Slightly lawful/very non-violent/very dishonest as a trickster, completely honest as a scholar. The Emissary of the Depth is a heroine.
Sophua Schulp is generally for lawfulness, but is willing to break laws she does not agree with. She is principally a pacifist, but knows that some villains cannot be reasoned with; still, even then, she tries to fight as nicely as possible. She is (in)famous for her impartialness as an expert witness/evaluator and her immunity to publication bias; as a heroine, however, she is a trickster, so be wary if you are a villain.

Motivations: To further science and civilisation, to prepare humanity for the Utopia of the Time of Tentacles, solving riddles, trickery

Faction(s) to which they belong: She is serving as an emissary of the Cephalopod Council, great cephalopod deities led by the Xnarl. She leads a "cult" (it's all roleplaying) of rationalist swashbucklers.

Origin/Source of Powers: Sophia Schulp was born with extreme intelligence. The Council of Cephalopods transformed her (note that her powers are biological, not magical)

Archetype and Known Powers: A heroic supergenius, mastermind and trickster. She is a universal genius, focussing on basic science and biology in particular, and can speak at the very least German, (King's) English, Latin (pronuntiatio restituta), Ancient Greek (Attic), Coptic, Akkadian and the Acoustic Cephalopod Auxiliary language (a "sign language" for beings who lack the colour-changing abilities of cephalopods; origin of names such as "Xnarl"*) and can read hieroglyphs, cuneiform and the actual Cephalopod languages. She also gained various other cognitive powers, such as precognition, although these are far less developed.
She has a "cult" of rationalist swashbucklers. Of course, they only pretend that they are a cult for fun.

Public Perception: the Prophetess of the Deep is notorious as a trickster disrupting evil schemes and even tricking villains into their doom. Sophia Schulpis also considered an exceptionally gifted, if extremely eccentric polymath.

Private Goals: Knowledge, furthering science and civilisation, preparing humanity for the Utopia of the Time of Tentacles

Physical appearance: The Emissary is a brunette, overweight (though not adipose) woman often displaying impishness. She is virtually never seen without her chameleonic mantle (if not camouflaged, resembles [I]Sepia officinalis[/I] in pattern), She usually wears a dark blue waistcoat (actually a jack of plates) and a domino mask cut to emphasise her impishness.

Catch Phrases:
"...the Utopia of the Time of TENTACLES!"
"Long Live the Cephalopod Council!"

History
It was soon obvious that Sophia Schulp was a woman of exceptional intellect (and an eccentric prankster).
Apparently, she did not go unnoticed even deep below the surface of the sea, as one day, Sophia experienced a vision where she was contacted by the Cephalopod Council. From then on, she seemed to see the world with greater clarity and detachment from humanity.
Nowadays, she is using her intellect for the good of civilisation not only as a scientist, scholar and advisor, but also as a trickster, defeating villains in battles of wits and illusions. She is also convinced that the Cephalopod Council will take over Humanity sometime into the future and create an Utopia known as the "Time of Tentacles".

“Super” v. Secret Identity: Sophia Schulp considers the Emissary of the Depth to be not a separate identity, but an office. She tries her best to keep prophecy out of her scholarship.

Personality:
Sophia Shulp is incredible curious and mischievous, traits further enhanced by her exaltation. She is also extremely xenophilic, while detached from normal humans.

Theme:
As I doubt anyone will volunteer to do so, there is no distinct one. The Cephalopod Council is associated with pipe organs, particularly the hydraulis.

*My real name cannot be pronounced, as it is not a sound, but consists of a set of visual characteristics in a cephalopod's appearance.