Third Drax

Drax's third incarnation was, much like his predecessor, a renegade Time Lord with a knack for tinkering and engineering. He hatched a con with his various future incarnations, raiding the most secure safe-house in history, using the Fourth Doctor and Romana II as pawns. (AUDIO: The Trouble with Drax)

Biography
Shortly after regenerating, Drax gained the map to Altrazar. In order to stage a con that involved the use of all ten of his future incarnations, Drax required a Blinovitch Limitation Effect limiter to avoid temporal catastrophe. Needing a fall guy, Drax conned the Fourth Doctor into stealing the limiter, which was what allowed his future incarnations to successfully cooperate on this scheme and others in the first place.

By the time the Doctor and Romana II realised that Drax must have known he would have been arrested over different incarnations, they realised the truth about McCormick and her men, and by the time they returned all of Drax's incarnations had escaped in their TARDIS. (AUDIO: The Trouble with Drax)

Personality
Drax showed great technological aptitude. However, he could not grasp temporal theory and failed the class. While Drax could not grasp temporal theory, he had worked out enough about the Blinovitch Limitation effect limiter to know its limitations and also to create an endless paradox with his various future incarnations to possess the device and also commit numerous crimes with two or more of his future lives.

He also showed disrespect towards the Laws of Time. (AUDIO: The Trouble with Drax)