Skarosa

Dr Skarosa was, as stated by Dr Chang, the founder of 3W.

He once played white noise through a translation matrix and heard three words – "Don't cremate me". Convinced that these were the voices of the recently deceased, he set up 3W on behalf of the dead as a way for them to communicate with the outside world. The Twelfth Doctor called him an idiot.

At some point Skarosa died, and leadership of 3W was either passed to, or usurped by, Missy. His body was kept in a dark water cell in the office of Dr Chang.

When Missy commanded "human kind bring out your dead", Skarosa stood in his cell. The dark water drained away to reveal that Skarosa's corpse had been upgraded into a Cyberman. (TV: Dark Water)