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"She approached the possessed horse, who lowered its head again and laid its face flat to her bloodied bodice in what might be submission, love or dementia."
―Demon behaves for Ista[src]

Demon was an ugly chestnut stallion with a fearsome temperament. He was Illvin's warhorse, despite Illvin's own evaluation that 'he was never any sane person's mount.' Illvin's name for the horse was too crude to share with Ista. It generally took three grooms, a blindfold, a curb bit and a twitch to control him, at least until Ista ordered him to behave.

It turned out that the horse was in-fact possessed by an elemental. Arhys rode him in his battle with the Jokonan sorcerers, and the horse survived because of demon-enhanced healing powers. He subsequently bonded with Ista, who accepted him as her new mount and gave him his final name.