Tremas

Tremas of Traken was one of the five Consuls of Traken to the Keeper of Traken of the Traken Union and at one time a candidate for Keeper.

Biography
Tremas married his second wife Kassia, who was also a consul. Nyssa was his daughter by his first marriage, with his first wife Lucina having died giving birth (it was implied that this was because of Nyssa's psychic powers causing particularly intensive birth trauma).

However, Kassia came under the influence of the Melkur and she turned against the Traken Union. When Tremas was considered unfit to become Keeper for helping the Fourth Doctor and Adric, Kassia was chosen and when she became connected to the Source, the power of the Keepers, she was destroyed and replaced by the Melkur, who it was revealed was really the Master. Tremas helped the Doctor stop the Master and still save the Source. After the Doctor left Traken, the Master still possessed some of the Keeper's powers after being removed from the Source to assist with the Master's assimilation of Tremas' body. (TV: The Keeper of Traken)

The Master (using Tremas' body as his own) posed as the Trakenite in order to fool Nyssa. (TV: Logopolis)

Tremas's fate greatly troubled his daughter Nyssa. Due to the Trakenite belief in the connection between the soul and the body, she believed that Tremas could never be at peace while the Master was using his form. (PROSE: Empire of Death)

Behind the scenes

 * "Tremas" is an anagram of "Master".