Sarissa becomes the asari Pathfinder after leaving Matriarch Ishara to die at the hands of the kett in order to bring a kett data module (which contained a map of routes through the Scourge) to ark Leusinia. Sarissa believed the data module would help the Leusinia escape the kett and that abandoning Ishara was a necessary sacrifice to save the lives of the many. Nevertheless, she keeps this a secret from the other asari, knowing it would disgrace her if they learned she did not go back to help Ishara when she had the chance. Sarissa justified the lie by telling herself her people needed to see her as a hero in order to keep morale up. The theft of the data module however, also causes the kett to send an elite hunter team called the Decimation, led by The Valiant, to pursue the Leusinia.
The stolen kett navigational data allowed the asari ark to flee through the Scourge while evacuating as many civilians as possible, but constant harrying from the Decimation eventually damaged the ark and forced the ark to go into hiding until rescue arrived. Pathfinder Ryder and Cora Harper can track down the Leusinia, aid the asari in repairing their ark, and fend off its kett boarders.
Pathfinder Ryder learns of Sarissa's actions after discovering an audio of Matriarch Ishara's succession log and has the choice of keeping the secret, exposing Sarissa but allowing her to remain a Pathfinder, or exposing Sarissa and replacing her with her second, Vederia Damali. If replaced, Vederia mentions to Ryder that Sarissa took her weapons and armor and left without a word.
If Sarissa remains a Pathfinder, Ryder can ask Sarissa what her goals are. Sarissa will inform Ryder that she intends to explore and chart the Scourge; and also use that information to drive the kett from their boltholes.
If allowed to remain as Pathfinder, Sarissa will participate in the battle for Meridian and can be seen shielding Initiative shuttles with her biotics. If Ryder has the support of all three non-human Pathfinders, Sarissa summons a biotic shield to protect the bridge of the crashing Ark Hyperion during the battle in the Meridian sphere, saving the life of Captain Nozomi Dunn.
- A sarissa is a long spear wielded by ancient Macedonian infantry.