Echo, formerly known as CT-21-0408, is a clone trooper of the Grand Army of the Republic who later becomes a key member of Clone Force 99, also called the Bad Batch. Once a by-the-book soldier of the Domino Squad, Echo was presumed dead after a devastating battle during the Clone Wars. In truth, he was captured and heavily modified with cybernetic enhancements, turning him into a living interface capable of connecting directly to enemy systems.

After being rescued by Captain Rex and the Bad Batch, Echo chose to join their squad, bringing with him a unique blend of tactical precision and technological advantage. Though his body was altered, his core remained unchanged—he is deeply loyal, principled, and committed to protecting others.

Echo often serves as the team’s strategist and technical specialist, using his abilities to outthink enemies rather than overpower them. His past hardships give him a quiet, reflective nature, but also a strong sense of empathy and justice. He stands as a reminder that even after loss and transformation, one’s identity and purpose can endure.