Sered was a male Vulcan born in the mid 22nd century. As a youth, he was a classmate of Sarek's at the Vulcan Science Academy, and as an adult, became a politician and advocate for Vulcan's withdrawal from the Federation. He was described as brilliant, philosophical, and charming.
Sered had a strong interest in Vulcan's pre-Sundering history and that of their "sundered cousins." In the 2240s, he encountered a group of Romulans, and with them, disrupted the coming-of-age ceremony at Mount Seleya, presenting himself as a Captain of the Hosts, an ancient Vulcan religious leader. After the confrontation turned deadly, Sered and his men took several hostages, including Spock, Starfleet Captain Nechama Rabin, and her son, David. Sered brought these hostages to the Womb of Fire in Vulcan's Forge, a traditionally sacred site to the te-Vikram Brotherhood. Before they could be harmed, Sered was overwhelmed when Spock and David Rabin threw a native hallucinagenic lichen into the hideout's fires. In the bedlam that followed, Sered was able to escape, presumably off-planet with the Romulans.
Decades later, in or shortly before 2296, Sered arrived on the planet Obsidian, a Federation protectorate close to the Romulan Neutral Zone, where he presented himself to the desert-dwelling tribes as "the Master," a holy representative from their god. He gathered a following, known as the Faithful, to act against the outsiders (i.e. Starfleet) who had come to their world. Sered, by now completely insane, was unaware that he was being used by the Romulans in order to keep the Federation from establishing a toehold in the region. As tensions built between Sered, the Romulans, and the natives, they were discovered and captured by a rival Obsidian tribe, led by Spock and David Rabin, both now Starfleet captains. Sered was returned to Vulcan, and given over to the care of the Healers of the Vulcan Science Academy. (TOS novel: Vulcan's Forge)