“The thunder of its hooves beats dreams into despair.” Nightmare is a potent ally. He is very protective, and can assess the magic energies around you to determine if there are any foreign energies around you and follow them back to the source to enact vengeance and generally make them unwilling to mess with you again. As fearsome as they appear, they are wonderfully comforting in the course of a bad dream, for they can chase away a nightmare as quickly as they can create one.
Nightmare is surprisingly affectionate, always up for poking his head over your shoulder and snorting sweet-smelling smoke in front of you when he’s in a good mood. He’s very easy to read, especially because of the smoky nature they have. When he’s in a good mood, there is nothing wrong and his light grey smoke smells very sweet. But if there are forces starting to appear around you, the smoke will darken and start smelling more burnt. They make wonderful alarms and ‘return to sender’ wardens.