Supreme Dalek (The Magician's Apprentice)

The Supreme Dalek was the leader of the Daleks on Skaro in the Dalek City.

He was the Dalek who took the privelege of Exterminating and Clara Oswald when they were captured and brought to the Daleks. He however ordered for a beamer to destroy the TARDIS.

He ordered the Extermination of the Twelfth Doctor after he had stolen Davros' wheelchair and mocked the Daleks, however it failed. He noted how the Doctor was against using weapons only to be scaled by the Doctor who wanted Clara back. This Dalek proudly professed that Clara was "not alive".

He later interrogated Missy, who survived by teleporting at the last second, about Clara's whereabouts, who had also survived. After receiving the Doctor regeneration energy, he praised Davros only to begin to panic about the sudden appearance decaying Daleks coming from the sewers due to them also being restored.

When the Daleks from the sewers began to rise above to the city itself and destroy the Daleks as revenge, he yelled for the Doctor to help them. He was ultimately destroyed by the angry decaying Daleks. (TV: The Magician's Apprentice/The Witch's Familiar)

Authority
He made all the greater decisions involving the Daleks and was the one who told the other Daleks to assist Davros when he pleaded for help. He also interrogated and spoke on behalf of the Daleks.