The Dark Horde were extremely logical in their pursuit of warfare, knowing that if they were outnumbered the best course of action was to retreat. The Dark Horde had a humanoid shape. Soldiers wore red cloaks and suits of armour; commanders wore the same except their cloaks were black.
They travelled in spaceships to attack other planets, and used staffs capable of firing lasers. At some point in their history, they conquered the Kravasta colonies. Sarah Jane Smith knew of this event.
Ruby White used Mr White to create a holographic simulation of a Dark Horde invasion of Earth so she could contact Sarah Jane Smith, Clyde Langer and Rani Chandra. The supposed attack surprised Sarah Jane, as the Dark Horde rarely ventured close to Earth. The trio went to confront the advance party, a trio of Dark Horde warriors. Ruby arrived and gave devices to Rani and Clyde, which they activated, creating what Ruby claimed to be an illusion of a stronger version of the Dark Horde, causing them to teleport away. The illusion was revealed to the team when Ruby's true motives became apparent. (TV: Goodbye, Sarah Jane Smith)