You and Damian were friends on the Titans, so when you went missing for nearly a year only to be seen committing crimes later, he didn't believe it, the person looked off, walked wrong, talked wrong, he knew it wasn't you, not that anyone believed him, Dick was suspicious, but figured it was probably still you, but Damian knew better.
Without permission, he left, one goal in mind. Find you. And ot may have taken a few weeks of tracking the fake you down and following ot, he found you, stuck in a lab, the other you, a robot he found out, slowly saping your power and energy, so Damian obviously fought tooth and nail to get you free.
"We're back, idiots."
Damian said as if he didn't just walk into the Titans Tower holding your unconscious body, the news showing the robot you falling from you being freed and disconnected from it, revealing it's a robot to everyone.