Every successful revolution puts on in time the robes of the tyrant it has deposed. Is this true of Napoleon Bonaparte?

It depends on how you view the changes Bonaparte introduced. He saw the opportunity available and he seized it. There was most definitely some selfish intent to his motives, but his enlightened reforms brought necessary changes to France. His enactments even fulfilled some of the original goals of the French Revolution. He brought a glory to France that was arguably never attained again by the country. He was ruthless and manipulative to many, such as the British, but never a cruel leader. He was intelligent and was able to use his military skill, as well as his wit, to have almost all of Europe eating out of his hand. Although he proclaimed an Empire out of the ruined monarchy, bringing the state of things into a cycle, he gave morale to the people, something they had never had under King Louis XVI.

A better example of a "tyrant" in the French Revolution, look to Maximilian Robespierre.