Carstairs

Carstairs was a cybernetic butler who helped the Cybermen convert people in their cloaked ship, before he was restored to his true self by the Doctor.

Character History
Carstairs came from an unspecified planet, but he was a happy man who cared for his family. He was taken by the Cybermen and partially converted: his emotions were wiped but physically he remained almost identical. He was then used as a butler onboard the cloaked Cybership designed to lure people in to be converted. When the Doctor and Jess arrived, Carstairs treated them as he treated all other guests. He converted two other guests, Harbergast and Hallowtime, before being restored to his old self by the Doctor with the help of a retrospective reader. He then fought off a number of Cybermen before sacrificing himself out of guilt by blowing the ship to pieces.

Season 1 (2015-2016)

 * 1) Horror of the Cybermen