FALL OF THE REPUBLIC
Also known as CT-1409, Echo was a member of Domino Squad on Kamino before graduating and joining the fight against the Separatists. He survived a Separatist attack on the Rishi Moon listening post, was decorated for bravery, and inducted into the 501st Legion. Echo and his fellow Domino, Fives, later helped defend Kamino against a Separatist invasion, and were promoted to ARC troopers after the Separatists retreated. The two also helped Anakin Skywalker and Obi-Wan Kenobi free prisoners from the forbidding Separatist prison known as the Citadel, a mission that cost Echo his life -- or so his friends believed.