The 3 Black Relics of Titan

"The various relics discovered across the solar system were manufactured by the unknown alien race called the Ancients. These black giants are planet obliterators. They ensure no life form can be born on the planet they land on.
Their deadly deed is over now but the origin of their power should be studied for it could be an invaluable asset in the war to come."
Amiral Vaughn - Centuries of war

PS; this is more 3d Coat fun for my project :)