Marcus Americanus Scriptor encountered a creature in Roma CLII. It was an enemy of the Great Houses, but was not theenemy itself. It could shapeshift. It appeared with a single, glowing eye. It bragged that it could not be removed from time, hurt by a black hole or a star, or bound by ritual.
The creature was hunting a group of twelve Homeworlders who had removed themselves from "the board". It had killed seven of them in different worlds before encountering Scriptor. Scriptor killed the creature with a sword, thrusting it into its glowing eye. (PROSE: Warlords of Utopia)