E'Tyshra was a T'Lani ambassador, who in 2370 represented her government in their request for Federation assistance in destroying Harvester weapons from their recent war. She, along with her Kellerun counterpart Sharat, conspired to eliminate all knowledge of Harvesters by eliminating all individuals involved in their disposal, including Julian Bashir and Miles O'Brien. Bashir and O'Brien however escaped to T'Lani III, and E'Tyshra ordered her soldiers to find them.
Meanwhile, she and Sharat informed Sisko that both had died after accidentally triggering a radiation pulse, providing a tape as proof. Sisko eventually discovered the deception and traveled to T'Lani III on the runabout Ganges. After he beamed Bashir and O'Brien aboard, E'Tyshra ordered the pursuit and destruction of the Ganges. E'Tyshra discovered too late that Sisko and the others had already beamed to the Rio Grande and escaped. (DS9: "Armageddon Game")