Ian McDiarmid as Fifth Master (2003) - Doctor Who The Master Fan Cast | myCast.io
Ian McDiarmid
Age: 82
male
Ian McDiarmid (born 11 August 1944) is a Scottish actor and director best known for portraying Emperor Palpatine in the Star Wars film series. He has received an Olivier Award for Best Actor and a Tony Award for Best Featured Actor in a Play for his performances. Wikipedia
Eventually landing on the Cheetah World, the Master became infected with the Cheetah virus, driving him mad. Eventually Tremas's body died reverting the Master back to his decayed form.
