Necrons

They have slumbered through the aeons, now across the galaxy, an ancient and terrible species is stirring back to life. On desolate worlds thought long-bereft of all life, ancient machineries wake into grim purpose, commencing the slow process that will see those entombed within freed to stride across the stars once again. 

More than 60 million Terran years ago, the Necrons shed their original organic forms and lost all forms of compassion and empathy. They have become instead ruthless, undying killing machines who are determined to exert their mastery over the galaxy once more.

The unstoppable, undying Necron legions are rising. Let the galaxy beware.