Sigma Team is a task-force division of Abstergo Industries. Led by Templar Juhani Otso Berg, the team was formed to hunt and kill the remaining Assassins following the Great Purge, though they had been wiped out on at least one occasion by their enemies.
In November 2012, Sigma Team attacked an Assassin cell in Florence, Italy. While the majority of Sigma Team was killed in an explosion, Berg escaped with some facial burns. The following month, Sigma Team was reformed and captured William Miles in Cairo, Egypt. Although the mission was a success, a member of Sigma Team reported Berg's abnormal behavior to Laetitia England and Ctibor Hašek. After conducting a debriefing of the operation, Berg stated he would discover the insubordinate.
In February 2014, Sigma Team tracked down Harlan Cunningham and Arend Schut after the two had stolen the Precursor box from Abstergo. Although the Assassins managed to escape, Sigma Team recovered the box. Nonetheless, the Templars had suffered severe losses, as Schut had managed to kill at least half the team. In September of that year, Laetitia disbanded and reassigned members of Sigma Team to other Abstergo operations. The following month, Berg requested that Laetitia revive his team, recounting his loss in Paris without the rest of his team. After being informed that Violet da Costa was busy in Montreal, Berg joined her in order to hasten her progress and get her to rejoin the team.
In 2015, Violet briefly left Sigma Team on the orders of Isabelle Ardant to assist Álvaro Gramática with his research into the Shroud of Eden. Later on, Sigma Team went to London, England to track down a Shroud located there. Subsequently, Berg and Violet held Assassins Rebecca Crane and Shaun Hastings at gunpoint when they attempted to confront Isabelle. But before they could execute the Assassins, a set of pre-planted explosives went off, allowing the pair to escape. When the Assassins Shaun Hastings, Rebecca Crane and Galina Voronina attacked Berg, da Costa and Isabelle Ardant in the chambers beneath Buckingham Palace, Sigma Team arrived to help them. However, they came too late to save Ardant and were single-handedly eliminated by Galina, allowing the Assassins to escape.
- Assassin's Creed: Initiates (first appearance)
- Assassin's Creed: Rogue
- Assassin's Creed: Syndicate
- Assassin's Creed: Origins