Anhora is the "Keeper of the Unicorns" and a powerful sorcerer.
AfterPrince Arthur Pendragon kills a unicorn, Anhora appears to him and Merlin. He tells them that although he has no power to lift the curse of the unicorn, he will put Arthur through a series of tests that could end the curse. Anhora first tests Arthur by using a man called Evan, a peasant of Camelot who sneaks into the Castle's food stores to steal a bag of grain; Arthur spares Evan from Uther's sentence of execution, thereby passing the first test.
Anhora later lures Arthur into the forest outside of Camelot, again by using Evan, who taunts Arthur until the prince attacks and kills him for insulting his pride. Anhora tells Arthur that his willingness to kill for his pride will cost Camelot dearly, and Uther soon after tells Arthur to stop rationing food to the residents of Camelot.
Merlin then seeks out Anhora in the forest, beseeching the old man to give Arthur one more test. Anhora offers to allow Arthur to prove himself in the Labyrinth of Gedref, but captures Merlin in the Labyrinth as well, delivering him to a rocky shoreline beyond the exit and waiting for Arthur to emerge. Anhora offers Arthur a choice between two goblets – one containing water, one containing poison – and explains that all of the liquid must be drunk, and that he and Merlin may drink from only one cup each.
Merlin proposes pouring the contents of one goblet into the other, thereby putting all of the water and poison in one cup so that it may all be drunk by one of them. Arthur does, drinking all of the poison and appearing to die before Anhora tells Merlin that Arthur is not dead – he has ingested a sleeping draught. But in proving that he was willing to die to protect a friend, Arthur proved that he was pure of heart, thereby lifting the curse (The Labyrinth of Gedref).
Anhora is a very powerful sorcerer, he could vanish and reappear at another destination at will, unlike all other socerers he used no incarntation for this spell. He was also able cast powerful spells such as ensnaring Merlin in a vine with a word, he could as conjour up an array of things, including food.
It is possible that he could take the form of another, possibly taking the form of Evan when testing Arthur. However since Evan was never confirmed to be Anhora, it is likely that Anhora could instead conjure illusions or apparitions which beared similarities to him which could have been Evan.
Although he repeatedly states that it is not in his power to remove the curse, he most likely means the rules state he can't till after the person proves his worth, as he plays a vital role in the curse, judging the person, and providing him with tests to see if he is worthy.
Although he is not the cause of the curse persay, it seems his power causes its effects, as he was able to undo it after the tests have been passed, this also shows his power, as Merlin was unable to break it, stating that the power behind it was greater than his powers.
- The name "Anhora" is a mistranslation of unicorn the exact translation is "Anhorna".