In his screening interviews, Tiran Kandros states he is named after an ancestor who captured a dreadnought in the Krogan Rebellions, and he was expected to live up to the name. After beginning boot camp at the traditional age of fifteen, Kandros rose through the ranks and was assigned to Sagirus Eight, one of the Hierarchy's counter-terrorism divisions.
Persistent rumors on the Nexus claim that Kandros was sent to investigate the Andromeda Initiative when the Hierarchy became suspicious about its activities. Kandros refuses to comment on former operations, citing family pressures as the reason he later joined the Initiative.
Pathfinder Ryder can ask Kandros to elaborate more on his reasons for coming to Andromeda and he will reveal that he was born into a typical turian military family. However, his sister and cousin both pursued other careers, so many of his relatives were proud he continued their tradition of military service. However, Kandros also wanted his own adventure and was enamored by Jien Garson's gutsy dream. Thus he made the decision to join the Andromeda Initiative.
During the early days of the Nexus' arrival, Kandros left the station to act as protection detail for a prospecting team and was captured by the kett. He managed to lead several other captives in an escape and returned to the Nexus, eventually founding a volunteer militia to defend the station.
According to Kandros, amongst all those captured by the kett that day, Kandros was the only person who managed to free himself, secure a weapon and rescue everyone. After breaking everyone out and returning to the Nexus, all the Nexus personnel started looking at him like he was in charge and the militia grew from there.
When Pathfinder Ryder first meets Tiran, he briefs them on the dire situation of the Nexus. He gives them a summary of the Scourge, the Nexus uprising, the Nexus being low on resources and successes, and how the Hyperion was the first ark they've encountered. He escorts Pathfinder Ryder to the other Nexus leaders so they can confer on a plan to save the Andromeda Initiative.
Should Pathfinder Ryder request for the militia's aid, Tiran will give Ryder authorization to dispatch his APEX Strike team.