When we learned of Darth Plagueis, also known as "The Wise," in Revenge of the Sith, his apprentice Palpatine (Darth Sidious) told Anakin that his mentor could manipulate the midichlorians (the life force of the universe) to control life and death itself. This is what lured Anakin to the Dark Side, as such a talent could allow someone to heal and even resurrect people. Since then, the going speculation has been that Plagueis used the Force to manipulate midichlorians and impregnate Shmi years later, creating the Chosen One -- not to be a savior, but a destroyer.
Instead of bringing balance to the Force, conspiracy theorists believed that Anakin was mystically engineered to tip the balance of power from the Jedi to the Sith Order. In Darth Vader #25, we now see how much credence that holds, although the master manipulator isn't Plagueis, but Palpatine himself.