Who Are the Aelfinn and the Eelfinn

[Caelan Arendor]

I never really understood these aliens; Aelfin foxlike and Eelfin snakelike. Are they living in another dimension or on another planet?

Aelfin answer questions with a special , not human-like insight.  They can disclose special thruths, disclose possible futures, but their answers are truthful within their own logic, but often twisted, distorted or incomplete.

The Eelfinn seem much more uncanny to me; their gifts often come at a very high price, for example when they can awaken or enhance special abilities and talents. They appear to drain strength and life essence from the supplicant. Overall, both races seem quite incomprehensible and hostile to me, and entering their sphere of power—whether intentionally or unintentionally—often has devastating consequences.
Can anyone provide a comprehensible characterization of these beings?

[Vambram]

In order to answer your questions, I went to Grok AI. The following are the responses from Grok:

 

Key characteristics of the Aelfinn:

Appearance: They are described as tall, slender, and unnaturally elongated, with pale skin, large black eyes without visible pupils or irises, and thin lips. They have an eerie, almost serpentine grace, which is why they are nicknamed “snakes” by those who have encountered them.
Speech: They speak in a slow, sibilant hiss (hence the “snake” association) and always answer exactly three questions per visitor.

Nature of their answers: The Aelfinn respond to questions about the past, present, or future with completely truthful answers, but they phrase them in an obscure, cryptic, and often misleading manner if taken out of context. They never lie, yet their answers are notoriously difficult to interpret correctly.
Price: In exchange for answering three questions, they exact a fixed price that is almost always something deeply personal—memories, physical attributes, emotions, or even body parts. The price is negotiated beforehand and is never monetary.
Location: They inhabit the same strange, sine-wave corridor realm as the Eelfinn, but occupy the half with the slanted yellow light and the four-spoked chambers. The Eelfinn’s half has red light and eight-spoked chambers.
Connection to the Old Tongue: Their name “Aelfinn” is derived from the Old Tongue and is sometimes translated as “the snake folk” or “those who come before dreams.”

They are bound by an ancient treaty (and poorly understood) treaty that limits what they may and may not do to visitors, which is why Mat, Moiraine, and others were eventually able to negotiate their way in and out of the realm a second time.
In summary, the Aelfinn are enigmatic, dangerous beings who trade absolute truth for a very high and often cruel personal cost, making any journey to seek their knowledge an extremely risky proposition.

 

Key Characteristics of the Eelfinn:

Appearance: Tall, slender, and unnaturally graceful, with bronze-toned or golden skin, pale hair, and large, dark, liquid eyes that evoke a fox-like quality. Their movements are fluid and feline, and they possess an unsettling, predatory beauty. They have sharp, almost canine teeth when they smile.
Speech: They speak normally (without the hissing sibilance of the Aelfinn), but their voices are smooth, musical, and deceptively pleasant.
Domain within the shared realm: The Eelfinn control the half of the dimension illuminated by red light, containing chambers with eight-spoked designs on the floors. The Aelfinn occupy the yellow-lit half with four-spoked chambers. The two races appear to maintain separate territories but share the same overall extradimensional space.

What They Offer
Unlike the Aelfinn, who answer exactly three questions with cryptic but always truthful responses, the Eelfinn grant exactly three requests. These requests may be for:

Physical objects (often of immense power or rarity)
Abilities or enhancements
Experiences or sensations
Information (though rarely straightforward)

The Eelfinn are notorious for fulfilling the letter of a request while deliberately perverting its spirit. Their gifts almost invariably come with unforeseen and often disastrous consequences unless the wording of the request is extraordinarily precise.
The Price
The Eelfinn do not negotiate the price in advance the way the Aelfinn do. Instead, they consider the “price already paid” by the very act of entering their realm. Historically, this has meant:

Feeding on emotions (especially fear, anger, hope, or passion) while the visitor is present
Taking memories, senses, or pieces of the visitor’s life
In extreme cases, claiming the visitor’s life itself if the ancient treaty is not invoked

They are bound by an ancient treaty (made long before the Age of Legends) that limits their actions, but only if the visitor explicitly knows and invokes the correct terms of that treaty.

The Ancient Treaty
The critical limitation on both Aelfinn and Eelfinn behavior is an extremely old treaty whose exact terms are poorly remembered. The key known clauses are:

A visitor may ask three questions (Aelfinn) or make three requests (Eelfinn).
The visitor must come of their own free will (no compulsion by channeling or drugs).
If the visitor knows and speaks the correct invocation, they may set limits on the price and demand safe passage out.

Mat’s ashandarei inscription and Birgitte’s fragmented memories are the primary sources that allow later characters to survive a second visit.
Summary
The Eelfinn are far more overtly malevolent and predatory than the Aelfinn. Where the Aelfinn trade in dangerous truth, the Eelfinn trade in dangerous desire. They are bound by ancient rules, but within those rules they are merciless tricksters who will twist every wish into a curse unless the supplicant is extraordinarily careful. Dealing with the Eelfinn is universally regarded, even by Aes Sedai of the Age of Legends, as an act of extreme desperation or hubris.