Fluid Morality

Scientists have discovered that magnets can alter a person's perception of morality. Granted, in this limited study, the change was minor and temporary, but we're writing science fiction here and this is the stuff of major bad guy weaponry. Why have Dr. Doomsday get off his evil genius backside when he can apply his magnetic mind altering device to a captured good guy and have said hero do the dirty work? Or does Dr. Doomsday alter the heroine's moral compass enough that she'd date him? If she does date him, how does that alter Dr. Doomsday's morality? Something about wanting a bunch of baby evil geniuses underfoot has a way of changing a man's priorities - if not his morality.