Rusty (Doctor Who)

Rusty is a recurring character in Doctor Who first appearing as the protagonist villain the episode "Into the Dalek" and appearing later as a minor yet important character in the episode "Twice Upon a Time".

He is rouge Dalek who is convinced by the Doctor to hate his own race sending him on a massive killing spree against every dalek he can find.

He was voiced by Nicholas Briggs who provides the voices for various other Doctor Who villains.

History
At first Rusty appeared as an ordinary Dalek before he was stranded in battle and after witnessing the birth of a star discovered his race to be evil and wished to destroy all of them. He was later apprehended by the Combined Galactic Resistance. The Doctor, Clara Oswald and a few others were shrunk down and sent inside of Rusty's damaged shell in order to repair a leaking gradation tank before his body would wind up killing itself.

The Doctor repaired the tank however Rusty became an ordinary dalek again and started attacking the nearby soldiers, the Doctor then restored his previous memories reverting Rusty back to hating his own race once again.

Rusty left the ship with the other Daleks fooling them into thinking that he was an ally when in fact he intended on exterminating all of them. He continued this work for billions of years to come before the Doctor found him once again.

Rusty was enraged to see the Doctor and continuously fired at him due to his belief that the Doctor was a "good dalek". The Doctor then called a truce and Rusty assisted him by entering the Dalek Pathweb as him helping the Doctor would torment the daleks.

Rusty gave the Doctor the information he wanted about Helen Clay and the Testimony program and the Doctor left shortly after, leaving Rusty to continue his assault on the Dalek race.

Trivia

 * He is often compared to Metaltron another reformed Dalek however there are several differences between these two characters.