I did the Doctors, why not the Masters as well?

Koshei: We just thought, “Look at that dried grass, let’s set it on fire.” That’s what you do when you’re twenty-five.

First: Is that hypnotism or just confusing the fuck out of them?

Second: I’d better burn it’s face so I seem normal.

Third: You really do seem like a spy, because you’re posh and a tiny bit gay.

Fourth: I had to force him, I couldn’t persuade him. He was dead.

Fifth: This is a 100% trustworthy face and it was telling the absolute truth.

Sixth: I would like five pints of bitter and a knife.

Seventh: I won’t kill you. I haven’t killed anyone for years.

What if the Master didn't regenerate at the end of Utopia, and the fifth master went on to play the antagonist in The Sound of Drums and The Last of the Timelords. Naturally, there would be tone changes given the different actors and the different personalities of the two different regenerations. The storyline would change with Jacobi as the master; an older man so friendly and so menacing at the same time. A jolly hypnotist who cheerfully mesmerizes an entire country into electing him their leader.

Simm still plays the sixth Master, when he returns in The End of Time. Here the Doctor faces a younger, madder Master whose very existence entreats him to remember his youth on Gallifrey. When faced with the time lock being broken, the Doctor remembers that the Master, the Doctor and Gallifrey have changed drastically since they were young.