Felix Kriegslieter

Doctor Felix Kriegslieter was the alias adopted in Nazi Germany by the War Chief after his aborted regeneration.

Origins
Examining his seemingly-dead body as they were retreating from the War Games planet back to the War Lord homeworld, the War Lords discovered that the War Chief was still alive. Wanting to study him, they threw the body in their ship's hold, where he began to regenerate. Because of the "massive injuries, the extensive tissue damage, the complete lack of all medical care", the regeneration aborted. This left the War Chief in a half-regenerated form resembling two bodies grotesquely fused together. His torso, which required extensive bandages, sprouting "twisted" stubs of extra limbs, and his head had a second, incomplete skull growing from the back of it, giving it an odd, enlarged shape. (PROSE: Timewyrm: Exodus)

As Doctor Kriegslieter
Having helped the War Lords to break the time loop the Time Lords had erected around their world, the War Chief helped them travel to Nazi Germany. Using a false beard and hair and highly protective clothing to disguise his warped appearance, he adopted the name "Felix Kriegslieter" and served as an occult advisor to Adolf Hitler, at the head of the Black Coven. His hope was to change history with the Nazis as his agents, believing that they were so vicious that they barely needed the War Lords' conditioning. (PROSE: Timewyrm: Exodus) One time, concerned with Hitler's health, Martin Bormann telephoned him. (PROSE: Players)

The Seventh Doctor later confronted the War Chief, prompting him to try to take the Doctor's healthy body and his six remaining regenerations. However, his efforts to replace Hitler with Heinrich Himmler were thwarted by Himmler's devotion to his Führer. This allowed the Doctor to alert Hermann Goering to "Kriegslieter's" betrayal and destroy the War Chief's base by overloading its nuclear reactors, the brainwashed Nazis falling to the superior initiative of their mentally free opponents. (PROSE: Timewyrm: Exodus)

Fate
In the final moments before his base at Drachensberg castle collapsed, Ace looked down and briefly glimpsed the War Chief engulfed in flames. With the new deadly injuries having seemingly reset his regeneration, he appeared healthy once more — "young, tall, dark and satanically handsome". (PROSE: Timewyrm: Exodus) Some accounts suggested that the Time Lord who had acted as the War Chief during the War Games incident had subsequently become the Master who menaced the Third Doctor during his exile on Earth, (PROSE: Doctor Who and the Doomsday Weapon, etc.) although during his encounter with Kriegslieter, the Seventh Doctor seemed to believe that he had not encountered the War Chief since the War Games incident. (PROSE: Timewyrm: Exodus)

Physical appearance
Due to his aborted regeneration, Kriegslieter's tall body was visibly malformed, resembling two bodies conjoined together; his torso bore injuries that required constant care, and sprouted "twisted" stubs of extra limbs. His head, likewise, had a second, incomplete skull growing from the back of it, giving it an odd, enlarged shape. As such, Kriegslieter was forced to wear a large cloak as well as a false, bushy white beard and wig, to disguise his deformed, dual body. He moved "surprisingly quickly" with "an odd, spidery gait - as if there might be eight legs rather than two under his cloak". His red lips were visible through the false beard. (PROSE: Timewyrm: Exodus)

Behind the scenes
In light of the suggestions in other stories that the War Chief was an early incarnation of the Master, it has sometimes been suggested that Kriegslieter is an interim between Edward Brayshaw and Roger Delgado, with his reset regeneration glimpsed by Ace at the end showing the beginning of his transformation into Delgado.

However, this does not appear to have been intended by Terrance Dicks, as lines in Exodus suggest that the Doctor had not met the War Chief since The War Games and believed him to be dead (although the lines could conceivably be interpreted as referring specifically to Brayshaw's incarnation). Contrary to a popular rumour to that effect, the phrase "tall, dark and satanically handsome" was not used anywhere by Dicks in the Target novelisations to characterise Roger Delgado's incarnation of the Master: it appears instead to be a description of Edward Brayshaw himself, thus depicting the War Chief's body's reversion to his earlier healthy form as he started to regenerate, rather than deciding the matter, one way of the other, of his next incarnation's identity.