Hedin

Hedin was a member of the High Council of the Time Lords. Hedin was also an old friend of the Doctor.

Biography
Like all Time Lords, Hedin was taken from his family at the age of eight for the selection process in the Drylands. Staring into the Untempered Schism as part of a Time Lord initiation rite, Hedin was inspired by what he saw in the Schism. (PROSE: A Brief History of Time Lords)

Out of sympathy for Omega's plight, Hedin helped carry out Omega's plan to bond with the Fifth Doctor and achieve physical existence once more. He shot Talor with an impulse laser, allowing him to remove the records of Omega's theft of information from the Matrix. When the Castellan attempted to kill the Doctor to prevent the bond from taking place, Hedin sacrificed his life to save the Doctor, allowing Omega to complete the bonding. (TV: Arc of Infinity)

Later, the Adherents of Ohm, a cult of Omega on Gallifrey, considered him a martyr and used the Crest of Hedin as a symbol. (AUDIO: Intervention Earth)