A young Force-sensitive Human male, Aldren Dayos was inducted into the Jedi Order and studied the ways of the Force. After passing Trials of Knighthood, Aldren was elevated to the rank of Jedi Knight during the beginning of the Second Sith War, a a devastating conflict that began when the Jedi Knight Revan, who had led the forces of the Galactic Republic to victory in the Mandalorian Wars, founded his own Sith Empire and declared himself the Dark Lord of the Sith.
In the year 3957 BBY, the Republic drafted a daring plan to deprive the Sith of their powerful and charismatic leader. By carrying out their scheme, they hoped to end the war prematurely by destabilizing the fledgling Sith Empire and giving the Old Republic Military time to rally its forces. Aldren Dayos was part of a strike team that were dispatched by the Jedi and Republic to the planet Sernpidal. Along with fellow Knight Anyara, Lieutenant Kagen Brendel, Mara Davos, Samar, and Lieutenant Haden Vazzar, Dayos and the team planned to obtain a code cylinder from the Sith Commander Doel Scherp, which contained the command codes for the sensor systems of Darth Revan's flagship. The agents learned of Scherp's location on the world, then confronted him and obtained the code cylinder. Eventually, the agents were able to contain the cylinder during an attempt to capture Darth Revan.
After the mission was complete, Dayos, Anyara, Brendel, Davos, Samar, and Vazzar managed to board Darth Revan's flagship and battle their way to the Security Command center. During the resulting fleet battle, Aldren and the entire squad encountered Darth Voren, along with fifteen Sith troopers and several Sith Marauders, who were all under his command. Engaging them, Aldren and his team managed to obtain the codes required to access the SecCom computer system, and they used them to order the Sith security teams to move to the left side of the ship, which gave Bastila Shan and her strike team to capture Revan. However, moments later, Darth Malak, who was Revan's Sith apprentice, decided to betray Revan and his ascension to the rank of Dark Lord of the Sith. Seeing his chance to usurp his Master's title, Malak ordered his gunners to open fire upon the bridge of Revan's command ship to eliminate Revan and all the Jedi onboard. After sending the codes safely to the Republic fleet, Aldren and his team were perished as the flag ship was destroyed by Malak's fleet while Bastila captured the critically injured Dark Lord and escaped the ship prior to its destruction.
Dayos was one of six pre-generated characters that were made for the module.