Straddling the line between Comics and Literature, Ysanne Isard of the X-Wing Series. She's not quite as good as a Magnificent Bastard, she's quite manipulative, she's the head of Imperial Intelligence and aware of the various things being planned, and many of her plans seem to hinge on letting the New Republic win an Imperial planet. Brentaal IV, she put a hopelessly incompetent admiral in charge so that opinion would turn against Sate Pestage and she could have him assassinated; in the process the planet was lost and the best Imperial pilot since Vader switched sides. Coruscant, she infected with a nasty virus and left to the New Republic. The New Republic found a cure. Then, well, here's a passage where another of her people defects.
"Madam Director Ysanne Isard, I regret not being able to bring you this message personally, but not that much. In the time I have been associated with you I have found you to be sociopathically self-centered, prone to irrational and impulsive reactions to situations, and prey to a preference for appearance over substance. I have no doubt these affectations were seen as skills by the late Emperor, and indeed may have enhanced your ability to comply with his orders, but by no means are these traits that make for great, or even adequate leadership."
- The cure was the whole idea. She planned for that, hoping to bleed the New Republic for the cure, and conquered the planet with the cure! She just failed to anticipate the New Republic beating her out, and the plan to bleed them out.. being a Gambit Roulette in itself.