Superior And Second
Their faces seemed out of focus - They appeared as if a plasma - shifting, changing, convulsing. They had the look of Supreme Fulfillment, when the Stolen Energy made its way to Them that are They.
They are able to Steal what you generically coin the soul - for starters. The list of what They CAN'T do will make things much easier - not much. They are the Essence of Nimbleness, and They are Fleet of Essence. They are That, which you as a species are Unprepared for and Incapable to Conceptualize in a Timely Manner.