Revenant

The Revenant is a powerful undead spirit, capable of posessing a dead body. It has magical powers, capable of throwing fire, raising the dead, teleport, and much more. IT also has the dubious honor of being both a being and beings as it posesses a dead body, so it has multiple bodies.

Revenant and the Horde
The Revenant has power over the Horde, whether it's because it's a more powerful undead or another reason remains to be clarified. As it is, it has attacked Tool and Bandit Camp, but Tool prevailed with the aid of part of his wolf pack. Tool slew the Horde present and then fought the Revenant, destroying the body it had at the time. The Revenant then left, promising it was not the last Tool's seen of him, presumably to take control of another body.

Revenant
It has appeared near Ancarve after a Horde attack, telling a group of people; composed of Gear, Alonya, Tool, Wanderer, and (aerogrand) that "The mountain spews fire as it awaits you, Youngling", refusing to say who was 'Youngling' or explain itself and soon left.