The unicorns are the most remote and mysterious of the magical races. They are few in number, and all of those live in a remote city in the Oraclean mountains. It is common for unicorns to travel into Reyern, there is even an embassy to Caer Aewyn, but they never allow humans into their city.
Unicorn magic is concerned with perfection. This is not a specific ideal, but a mutable concept. A skilled unicorn can make an object that is perfect for a purpose. The perfect merlot grape to impress a lord, the perfect necklace to attract a prince or the perfect sword to kill a king.
Something less well known is that unicorns in their natural form can see magic. Like Source mages they are able to see active magical effects and locate sources of stored magic, such as magical artefacts or source stones.
In their natural form, unicorns cannot communicate with humans. They have no spoken or written language because they communicate entirely by a form of telepathy that even air magicians cannot hear. Unicorns have a human form which they take in order to mix and communicate with humanity. Unicorns in human form are unusually pale, with pure white hair and a vestigial horn on their forehead.
It must be remembered that unicorns are not human and do not follow human morality. They see no issue with using their magic on other creatures without explaining the full consequences. The perfect artist may be completely insane, while the perfect warrior could well be a sociopath. This is not simply a case of being careful what you wish for, it is simply that humans are inherently flawed. A human who is ‘perfect’ is no longer entirely human.
Unicorns can take human form, and so can breed with humans. Half-unicorns are a little closer to perfection than other people.