Borusa has been known to the Doctor by many faces on his ascent to the highest office of Gallifrey – the presidency, having regenerated a number of times and having held many different titles and jobs.
His earlier regenerations belied a benevolent ruler and supporter of the Doctor. He first appeared in The Deadly Assassin – 1976 helping the Doctor uncover a Master-driven plot to overthrow the Timelord high council.
He had taught the younger First Doctor at the academy – and the Doctor respected him as a lifelong ally.
His last regeneration though, in The Five Doctor’s – 1983 changed him into a despotic power monger. He kept the Harp of Rassilon as a keepsake in his President’s office, as if he inspired to become more powerful than the Timelord’s despotic founder.
He offered the Master a new life cycle if he would help the Timelord’s aide the Fifth Doctor in his journey through the Death Zone to Rassilon’s tower.
He also procured the forbidden “Black Scrolls” from the archive (a forbidden Timelord text) and used them to frame the Castallan, when the Doctor was getting closer to unmasking him.
His final undoing was accepting the immortality offer in the tomb of Rassilon – believing it to be a prize and was turned to stone to forever adorn the side of Rassilon’s tomb.
Borusa’s title of Lord President was then offered to the Doctor, who turned it down and Chancellor Flavia became Lord President in his absence.
