Doctor Who: EVERY Version Of The Master Explained
7. The War Master (First Appearance: 2007)
The War Master was the first Master in the modern era of Doctor Who.
Once again played by Sir Derek Jacobi, the Series 3 episode Utopia found this Master at the very end of the universe, where he was disguised as the kindly Professor Yana. But unlike the Master's other disguises, Yana wasn't aware of who he really was.
At an unknown point in the past, the Master had used Gallifreyan technology called a Chameleon Arch to store his true consciousness inside a fob watch, with the human Professor Yana being little more than a mask. The Master did this to hide himself away from the destruction of the Time War, the great war between the Time Lords and the Daleks, due to being too scared to face it himself.
The interesting thing about this incarnation of the Master was how Doctor-ish he became when hiding as Professor Yana. He uses his scientific genius to try and save the last of humanity from extinction, and it's only once he opens the fob watch and becomes a terrifyingly sinister Master – played to perfection by Derek Jacobi – that his true colours are revealed.
This Master only appeared in a single episode due to being gunned down by his assistant Chantho. He regenerated inside the Doctor's TARDIS, which dematerialised and took him back to 21st century Earth.