The Eminence

The Eminence was a gaseous entity that travelled across the universe in teleportation caskets. The Eminence could control the minds of any being it came into contact with, as long as it inhaled the breath of forever, turning them into its infinite warriors. (AUDIO: The Seeds of War)

Biography
The Doctor fought the Eminence in his fourth incarnation.

The Eminence spent many years at war with humanity. The planet Kalsos was on the front lines of the war.

The Sixth Doctor once stopped the Eminence from infecting Earth's seed banks, thus rendering the Earth's colonies barren. (AUDIO: The Seeds of War)

Around a thousand years later, the Eminence resided at the edge of the universe. The Orpheus travelled to the Eminence's location and attempted to siphon its power in order to get home. The Eminence began to possess the crew of the ship.

The Eighth Doctor teamed up with the Daleks against the Eminence. The Dalek time controller used the weapon they had built on Nixyce VII to destroy the Eminence. (AUDIO: Time's Horizon)