The Moirae (singular Moira) are the recondite Fae of Arcadia, embodying the Arcanum of Fate, and can be called down with the use of Supernal Summoning.
Due their volatile and capricious nature, Moirae can take any form when they're summoned and even change this form within the blink of an eye, and no living mortal mage has ever seen their true form.
Knowledgeable about Fate itself, they have many talents a summoner might find useful. Among a score of possible benefits, a mage calling upon a Moira can gain a greater understanding of the nature of destiny. Mere proximity to a Moira can alter the destiny of the mage, ultimately leading her to new discoveries and conclusions. They always speak the truth, but often a truth that is harmful or unpleasant.
As they are still Fae, a mage have to be cautious what he says and when he says something, otherwise the Moira could ensnare him with a fate that could be unpleasant.