C is for... Cho-Je

Cho-Je was a Tibetan monk who helped to run a meditation centre in the English countryside. Its master was the elderly K'anpo Rimpoche. Mike Yates went to stay at the centre after he had resigned from UNIT following the Operation Golden Age affair, in order to sort himself out. He invited Sarah Jane Smith down as he was suspicious of a man named Lupton and his followers, who were conducting secret ceremonies in the cellar. Mike thought it worthy of investigation by UNIT, but felt he couldn't contact them direct. Lupton had established contact with a race of giant spiders on Metebelis 3, and their ruler - the Great One - wanted a crystal which the Doctor had taken from the planet.
Cho-Je tried to warn Lupton but he and Mike were blasted by one of the spiders.
When the Doctor met K'anpo, he recognised him as a fellow Time Lord - his old mentor who had taught him as a child. He had lived the life of a hermit, away from Time Lord society, and had left Gallifrey by mentally transporting himself away, rather than use a TARDIS. The spiders killed K'anpo, but Sarah saw him regenerate into Cho-Je. It transpired that the younger monk had been a projection of the old Time Lord all along - a shadow of his future self.
When the Doctor returned to UNIT HQ after confronting the Great One in her lair, he was dying from radiation. Cho-Je / K'anpo materialised in the UNIT lab and assisted the Doctor in regenerating for the third time.

Played by: Kevin Lindsay. Appearances: Planet of the Spiders (1974).

• Lindsay had appeared earlier in Season 11 as Linx, the Sontaran warrior, and would return for the final time the following year as another Sontaran - Styre.
• The Doctor would get a future projection of himself at the time of his next regeneration - the Watcher - though this would be an intermediate stage between the Fourth and Fifth incarnations.
• Choje Akong Rinpoche (1940 - 2013) was the first Tibetan Buddhist Lama to establish a Tibetan monastery in the West (in southern Scotland in 1967).