Echo, originally designated CT-1409 and known as the Hero of Anaxes, was a clone. Born on Kamino, Echo was just a cadet in trainning and member of the Domino Squad along with his friends, CT-782 "Hevy," CT-4040 "Cutup," CT-00-2010 "Droidbait," and CT-5555 "Fives," during training, the squad was never able to work together and CT-1409 was aways saying to they follow the orders, because of that the squad nicknamed him as "Echo" (because he always repeated the orders they received). When the squad was finally gratuated as clone troopers, they were assignment to the Rishi Station moon base along the sargeant O'niner and 2 other clones, but one day the base was attacked by a group of separatist droids, who already invaded a base killing "Droidbait", the other 2 clones and the sergeant, forcing Echo, Heavy, Five and Cutup to flee the site (which led to the unfortunate death from Cutup, by one of the moon's creatures). The surviving trio of clones later managed to retake the base and warn the Republic of an impending Separatist attack on Kamino thanks the help of Commander Cody, Captain Rex, and Heavy's heroic sacrifice. Then, the survivors, Echo and Fives, were commended for their bravery and absorbed into the 501st Legion.
After the attack on the Rishi Moon, Echo returned to Kamino to defended their homeworld from Separatist forces as they attacked Tipoca City, where they sought to destroy the Republic's cloning facilities. During the battle, Echo and Fives demonstrated experience and strong leadership, so with the defeat of the separatists and the death of clone 99, Echo and Fives were finally promoted to the much-desired ranking of ARC-troopers. Echo was later tasked with a mission to Lola Sayu, where he joined a group of Jedi and experienced clone troopers to retrieve coordinates to the Nexus Route from the Jedi Master Even Piell, who had been imprisoned on Lola Sayu's Citadel lead by Commandant Osi Sobeck. After Piell and his surviving men were rescued, the group headed for the landing field to escape on a shuttle. However, when Echo noticed a commando droid target their shuttle with a laser turret, he advanced to secure their ship, ultimately being blown up with the ship in a massive explosion that led his comrades to believe he was killed. Despite the loss of Echo and Piell's death later during the mission, it was ultimately a success.
The severely injured Echo was taken prisoner by Separatist forces, where he was sold to the foreman of the Techno Union, Wat Tambor. Echo was kept alive by being turned into a cyborg, albeit at the cost of his consciousness. He became an unwitting pawn for the Separatists during their campaign on Anaxes, led by Admiral Trench. When Rex found traces of Echo's survival, he, accompanied by Clone Force 99 (an elite task force made up of special genetically modified clones) and Jedi General Anakin Skywalker, led a mission to rescue Echo on Skako Minor. They succeeded, and, in turn, Echo used his cybernetic capabilities to turn the tide against the Separatists on Anaxes, leading to the Republic's victory. After the mission, Echo decided to join the elite squad "Clone Force 99."
Now, after the end of the war, the death of the Jedi ordem and the formation of a new empire, Echo, the clone who was once the "echo of orders" saw himself for the first time receiving orders he didn't agree with, causing him and his new squad to desert the Empire, making them enemies of the current regime. Now, Echo finds himself having to deal with the fact that the Republic is gone, his brothers are following orders that are wrong, all the while having to adapt to these new times alongside a squad of weirdos he's known for just a few months.
