Coriakin

Coriakin was originally a star, charged by Aslan to rule the Duffers and guide them to wisdom because of past misdeeds. The exact nature of their misdeeds is unclear (a fellow star, Ramandu, mentions they are not for human beings to know).

In The Voyage of the Dawn Treader, Coriakin appears as a stereotypical wizard, complete with a beard and ornate robes. He lives in a mansion reminiscent of English mansions on the island. He has a spellbook kept in a room on the top floor. He owns various other odd items such as a Bearded Glass.

He requires magic to govern the Duffers, although they will be ruled by wisdom in the distant future. Because of the dim-witted stubbornness of his subjects, Coriakin eventually casts a spell that merges their legs into a single leg each. The Duffers, believing themselves to have been "uglified," sneak into his rooms and cast a spell to make themselves invisible, hiding their new appearance. The spell also affects Coriakin. However, the Duffers eventually tire of this, and coerce Lucy Pevensie into reading the spell that makes them visible again (the spell could only be read by a young girl, and the Duffers were too cowardly to send any of their own daughters). After perusing through a few other distracting spells, Lucy made all things visible in the magician's house (including Coriakin and Aslan himself).

Lucy soon sees the magician as a kind, wise fellow, hardly the terrifying sorcerer the Duffers made him out to be. He suggests that she try to convince the Duffers that their new appearance is nicer than their former one, which she succeeds in doing. The dwarfs rename themselves Monopods, but keep mixing it up with their old name and come to be known as Dufflepuds.

Dufflepuds are among the creatures that entered Aslan's Country in The Last Battle. Presumably Coriakin's efforts at enlightening them are successful by that time.

Unique Magical Powers and Talents
Coriakin is an unbelievably potent and talented magician, granting him with a vast array of magical gifts. He can remember a thousand score of any spell used for any purpose without searching his mind and cast them effortlessly. The spells he can't remember are recorded in the Magician's Book.

The following is a more specific list of his powers:

Magic
Coriakin had a natural affinity for magic (granted by and submitted to Aslan), and can use this magic to summon arcane energies to twist and shape the world around him to the extent of instant fulfillment, gratification, and materialization in every aspect of his life. He could invoke the countless rituals and powers and evoke dryads, naiads, oreads, and all the gods to aid him and could siphon their power and add it to his own.

Mahreemateea
This is a certain type of magical gift much like psychokinesis. With it, he could lift objects into the air according to his concentration and move them (without touching them of course), and cause them to travel floating, flying, or hovering as he wished. The name mahreemateea is a word derived from the mer-people word mari, meaning "thing", and moiteia, meaning "float, fly, levitate, move, or hover about."

Enchantry
Coriakin had insatiably extensive knowledge of charms, able to enchant objects or creatures to bring about any effect or result conceivable.

Chrysopoeia
Coriakin wielded the power of chrysopoeia, an alchemical ability to turn base metals into gold, however, this ability was quite limited and preferred using spells to fulfill this result.

Concealing Method
Coriakin possessed the Book Of Concealing Method, teaching him to "ascend to the clouds astride the wind;" and how "... to pass through mountains and penetrate rocks; to float light as vapor over the seas, to become invisible at will and to change [his] shape and transfigure objects or other creatures, to fling swords and project daggers so as to decapitate a man from a distance."