Erra is a high ranking Sentient. Son of Hunhow, and older brother of Natah. Late in the Old War, Erra led an assault on Lua alongside another Sentient, presumably Hunhow. He reached a cave full of Reservoirs, where he grabbed a still living Dax by her head. When the Lotus, surrounded by six Tenno ordered him to let her go, Erra was devastated at seeing her current self now siding with the enemy, and tried to make her remember who she used to be as Natah and return to his people's side.