2. Her Schemes Worked
BBCPractically every villain on Doctor Who has concocted wild schemes at some point in their history on the show. A few of them even lasted as the victor for a while, but never has a scheme lasted as long as something the Rani devised. Looking back over her televised appearances (and even including the novels and audio adventures if you're so inclined), her list of successes is far longer than her list of failed schemes. The ambition we mentioned earlier is truly an impressive force, driving her to attain achievements that most villains wish they could accomplish. Nothing is more dangerous than a villain who actually gets things done, hence the Doctor's determination to halt the Rani's plans. Although the Doctor always succeeds in doing precisely that (he's the Doctor; that's what he does), the Rani plans have been in motion for a while by the time he shows up. He simply pulls the plug on something that was already working.