Unicorns were deadly, pure equids that bore alabaster coats and single spiralling horns atop their heads. They were favoured beasts of Proteus. During the War of Humanity, they were matched, along with the Scrula, against the Triumvirate's legions of Nevaharr. Later in the war, their defensive magics would be largely what supported the Gods' defences against Pazuzu's Inferno Legions. Han-Tolneth eventually arrived with Ashaxei and the other Greater Dragons, but not before the unicorns had all fallen dead, their magics overwhelmed by the demonic assault.
As punishment for his crimes, Agatheis was transformed into a unicorn, most of His intelligence and power stripped. Millennia later, the captive god touched His horn to the Hammer of Phaestus, awakening Phaestus the Smith from His slumber. This act was deemed worthy of freedom by the Logos, and Agatheis was returned to His original form.