Brainiac has taken many forms over the years in the ever changing DC Universe, but regardless of his different origin stories, this Superman villain has always pushed the Man of Steel to his limits. Obsessed with shrinking and collecting parts of different worlds, the villain has set his sights on Metropolis on multiple occasions, and even has a piece of Superman's home planet. When that was restored to its full size, the hero finally found a home with his people on Earth, but rather than lose it from his collection, Brainiac didn't hesitate in destroying it and every Kryptonian who lived there. As a alien villains go, he's one of the worst.
